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BOSTON 

PUBLIC 

LIBRARY 


?■' 


"BOSTON  PUBLIC  LIBRARr 


SOUTH   AREA    PLANNING   STUD 


BOSTON,  MASS. 


AUGUST  1978 


"BOSTON  PUBLIC  LIBRARr 

WO  ^  \ad/im^  c/ijV€l^,  .^6<U^my  02//4 


August  16,  1^ 


DO 


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HO"^ 


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.\^\OMt 


Mr.  Norman  Van  Ness 
Division  Administrator 
Federal  Highway  Administration 
100  Summer  Street   Suite  1517 
Boston,  Massachusetts  02118 

Dear  Mr.  Van  Ness: 

The  attached  documents  constitute  Corridor  Planning  Studies  of 
the  proposed  improvements  to  the  Central  Artery  in  the  Central 
and  South  Areas  of  the  Corridor.   The  study  was  undertaken  by 
the  Commonwealth  to  determine  feasible  corridors  and  alterna- 
tives.  Based  on  the  technical  work,  and  following  a  series  of 
meetings  with  agencies,  individuals  and  community  groups,  I 
find  that  the  projects  are  feasible  and  should  proceed  into 
environmental  impact  analysis,  for  reasons  cited  in  the  document. 

The  focus  on  the  Central  Artery  has  emerged  from  a  decade  of 
examination  of  local  and  national  transportation  policies .   This 
examination  has  yielded  the  following: 

1.  We  have  moved  from  a  search  for  new  alignments  for  addi- 
tional urban  expressways  to  detailed  study  of  how  to 
improve  service  levels  in  all  modes  of  transportation. 

* 

2.  Analysis  of  the  existing  highway  network  has  revealed 
several  serious  bottlenecks  in  the  system  serving  Eastern 
Massachusetts.  These  must  be  corrected. 

3.  Chief  among  these  is  Boston's  Central  Artery,  a  2.5  mile 
stretch  of  highway  that  carries  more  traffic  and  experi- 
ences more  accidents  than  any  other  comparable  stretch 
in  the  state.   In  addition  to  serving  as  the  sole  north- 
south  expressway  within  Route  128,  the  Artery  connects 
with  Storrow  Drive,  the  harbor  tunnels,  the  Mystic  Bridge 
and  the  Mass.  Turnpike  and  serves  most  of  the  traffic  to 
Downtown,  the  seaport  and  Logan  Airport. 


-  2  - 


Mr.  Norman  J.  Van  Ness 


August  16,  l'^78   ,-' 


Because  the  Central  Artery  is  the  predominant  road  facility  in 
the  region,  alterations  made  to  it  will  affect  the  regional 
economy  of  the  Boston  Metropolitan  Area,  which  is  expected  to 
grow  by  3.5%  per  year.   For  example,  if  the  Central  Artery  is 
not  reconstructed,  and  the  growth  of  the  regional  economy  were 
retarded  by  as  little  as  0.1%,  the  region  would  permanently 
lose  $1,080,000,000  over  the  40-year  life  of  the  facility. 
Obviously,  it  is  difficult  to  pinpoint  this  type  of  figure. 
The  environmental  and  engineering  analysis  to  be  undertaken 
will. attempt  to  define  in  closer  measure  these  economic  impacts. 
The  lack  of  improvements  to  the  Artery  would  potentially  mean 
no  growth,  with  severe  negative  economic,  social  and  environ- 
mental consequences  for  the  region. 

Plans  to  improve  the  Central  Artery  have  been  moved  forward  in 
an  effort  to  ensure  that  this  vital  link  in  Eastern  Massachusetts' 
highway  network  can  fulfill  its  critical  transportation  function, 
thereby  enabling  the  region  -  and  particularly  metropolitan 
Boston  -  to  realize  the  full  economic  growth  potential.   This 
work  has  been  underway  for  seven  years,  during  which  feasibility 
analyses  have  demonstrated  the  problems  and  potential  of  the 
facility.   It  has  been  part  of  a  process  reflecting  local, 
regional  and  state  growth  and  development  policies,  which  are 
mirrored  in  new  federal  urban  policies  as  well.   I  have  reviewed 
these  policies  below  to  demonstrate  the  integral  role  which 
Artery  improvements  have  in  the  continuing  development  process 
in  Boston  and  in  Massachusetts. 

Relation  to  State  Policies 


Massachusetts  has  been  a  leader  in  developing  state  growth  and 
development  policies  in  concert  with  local  communities.   These 
have  been  defined  both  by  present  and  past  gubernatorial  admin- 
istrations, and  also  by  the  joint  efforts  of  the  state  legislature, 
municipalities,  and  regional  planning  and  development  organizations. 
The  policies  which  have  resulted  are  nationally  known  for  their 
emphasis  on  the  revitalization  of  older  urban  centers,  with  a 
redirecting  of  state  and  federal  assistance  to  this  end.   The  state 
has  acknowledged  its  responsibility  to  assist  this  process  through 
targeting  state  investments  to  focus  on  older  developed  communities, 
through  the  infusion  of  new  jobs  in  these  areas,  and  through  growth 
management  and  economic  development  investments  which  are  within 
control  of  the  state.   A  great  many  documents  record  this  process 
and  fully  illustrate  the  emergence  of  these  policies.   On  the  state 
level,  a  Development  Cabinet,  consisting  of  the  Lieutenant  Governor, 
the  Secretaries  of  Manpower  Affairs,  Communities  and  Development, 
Transportation  and  Construction,  Environmental  Affairs  and  Consumer 
Affairs,  and  the  State  Planning  Director,  who  serves  as  Chairperson^ 
has  formulated  an  economic  development  program  for  Massachusetts.   ^ 


-  3  - 

Mr.  Norman  J.  Van  Ness  August  16,  197  8 

In  this  program,  Artery  improvements  have  been  identified  as  a 
critical  work  program  element  for  the  state.   The  Office  of 
State  Planning,  in  conjunction  with  the  state  legislature  and 
virtually  all  of  the  cities  and  towns  of  Massachusetts,  has  been 
instriomental  in  integrating  local,  regional  and  state  growth 
policies.   These  give  further  emphasis  to  the  important  roles 
of  our  older  urban  centers  and  the  need  for  the  state  to 
strengthen  and  revitalize  these  places  through  strategic  public 
investments,  along  with  encouragement  of  private  investments 
based  on  the  existing  and  improved  public  infrastructure.   Other 
state  development  policies  have  been  profoundly  influenced  in 
these  directions,  and  include  the  state  energy  conservation 
program,  industrial  development  strategy,  coastal  zone  manage- 
ment program,  and  a  battery  of  policies  concerned  with  enhancing 
the  economic  strength  and  environmental  quality  of  the  state's 
developed  areas . 

Relation  to  Regional  and  Local  Policies 

Within  the  Boston  metropolitan  area,  regional  and  local  policies 
have  emerged  to  reinforce  the  state  policies.   For  transportation, 
the  broad  state  policies  serve  as  a  guide  for  specific  plans  and 
programs  which  are  part  of  the  continuing  planning  process. 
Arteirf  improvements  were  first  suggested  by  the  City  of  Boston 
some  years  ago,  and  the  state  has  been  supportive  in  advancing 
the  concept  of  improvements  within  the  context  of  local  and 
regional  goals.   The  state  funded  preliminary  feasibility  analyses 
undertaken  by  the  City,   Subsequent  regional  plans  have  reflected 
this  joint  interest  and  the  proposal  for  improvement  of  the  Artery 
has  been  included  in  all  federally  required  transportation  certi- 
fication documents  produced  over  the  past  several  years,  and  has 
met  with  approval  of  the  six-agency  Metropolitan  Planning  Organi- 
zation.  Furthermore,  the  proposed  improvement  has  been  integrated 
with  regional  plans  for  open  space  improvements,  water  quality 
management,  economic  growth  and  with  the  current  focus  on  transit 
and  roadway  improvements  in  and  around  the  Core  of  the  region. 

Boston's  Downtown  is  important  to  the  present  and  future  of  the 
region  -  it  contains  300,000  of  the  City's  500,000  jobs  and 
represents  23%  of  the  metropolitan  area's  1.3  million  jobs  and 
13%  of  the  state's  2.4  million  jobs;  it  provides  $5  billion  of 
the  $7.5  billion  of  earned  income  for  the  City,  $20  billion  for 
the  metropolitan  area,  and  $36  billion  for  the  state. 

Programs  of  the  City  of  Boston  are  closely  integrated  on  both 
policy  and  organizational  levels  with  potential  Artery  improvement. 
The  City  has  a  long-standing  strategy  of  using  public  policies  and 


-  4  - 

Mr.  No-rman  J.  Van  Ness  August  16,  1978 

( 
investments  to  leverage  private  investment  in  the  Downtown  area. 
Urban  renewal  programs  which  began  the  process  of  Downtown 
revitalization  are  now  being  completed.   Five  major  renewal 
projects  have  been  undertaken  Downtown,  and  all  are  immediately 
adjacent  to  the  Artery  Corridor.   New  projects  which  are  being 
developed  will  fill  gaps  along  the  Corridor  and  strengthen 
residential  and  commercial  uses.   Other  new  developments  are 
taking  place  in  areas  adjacent  to  Downtown  where  the  Artery 
serves  for  principal  access.   They  are  located  in  part  on 
federally-decommissioned  lands  and  are  designed  in  significant 
part  'to  replace  lost  jobs.   When  implemented  they  will  supple- 
ment the  existing  annual  Downtown  payroll  of  approximately 
$3,000,000,000  with  an  additional  input  of  23,000  jobs  and 
$250,000,000  annual  payroll.   As  these  projects  develop,  the 
City  anticipates  an  infusion  of  over  $1  billion  in  private 
investment  in  Downtown  and  adjacent  areas.   Improvements  to  the 
Artery  will  strengthen  access  and  other  public  infrastructure 
in  all  of  these  areas  and  .will  assist  physical  development  by 
including  private  investments  in  the  core  of  the  region. 

Many  of  the  proposed  physical  changes  have  been  noted  in  the 
Corridor  Planning  Study,  and  the  Artery  proposals  have  been 
developed  in  concert  with  the  City.   The  City  of  Boston  initiated 
the  proposal,  and  plays  a  special  role  through  its  representation   /* 
on  the  Artery  Policy  Committee  and  has  a  uniquely  strong  role  in    V 
regional-level  policy  making  through  its  membership  on  the  Joint 
Regional  Transportation  Committee,  the  Metropolitan  Area  Planning 
Council  and  the  MBTA  Advisory  Board. 

Relation  to  National  Policies 

Proposals  to  improve  the  Central  Artery  are  not  only  consistent 
with  local,  regional  and  state  development  policies,  but  also 
with  federal  policies.   The  Commonwealth's  policy  for  the  revital- 
ization of  older  urban  areas  has  in  fact  preceded  the  development 
of  a  parallel  feature  of  the  Carter  Administration's  national 
urban  development  policy.   The  present  national  policy  cites 
Boston  as  one  of  its  target  areas  -  a  city  with  high  unemployment 
and  declining  population.   Federally-assisted  investments  in 
transportation  and  other  areas  will  be  trageted  toward  revital- 
izing urban  centers  so  that  investments  can  reinforce  one  another. 
In  undertaking  such  an  investment  policy,  the  federal  goal  is  to 
work  in  partnership  with  state  and  regional  agencies  in  furthering 
locally-defined  development  goals. 

Massachusetts  has  assisted  in  the  development  of  policies  aimed 
at  reducing  urban  sprawl  and  reinforcing  the  economic  vitality  of 
existing  urban  centers.   It  has  also  found  means  of  cooperating 


C 


-  5  - 

Mr.  Norman  J.  Van  Ness  August  16,  1978 

in  the  planning  and  implementation  of  transportation  improvements 
as  an  integral  element  in  the  strategy  to  encourage  economic 
growth  and  development  while  improving  environmental  quality. 
Since  these  are  now  federal  goals,  they  are  supported  by  city, 
regional  and  state  commitments  to  maintain  and  upgrade  the  public 
infrastructure  as  a  positive  inducement  to  private  investment, 
and  to  increase  potential  job  opportunities.   As  stated  in  the 
National  Urban  Policy  Report,  we  intend  to  "use  transportation 
as  an  incentive  program  to  leverage  public  and  private  urban 
revitalization  activities  and  make  urban  transportation  programs 
more  effective  tools  to  accomplish  improved  transportation  and 
broad  economic,  environmental  and  social  goals."   Proposed  improve- 
ments to  the  Artery  mesh  closely  with  these  federal  goals.   In 
addition,  in  every  instance  where  federal  guidelines  or  policy 
directions  have  been  applicable,  we  have  guided  or  modified  our 
proposals  to  assure  that  they  are  consistent.   These  include, 
but  not  limited  to,  such -varied  guidelines  and  controls  as  the 
Environmental  Protection  Agency  Air  Quality  control  provisions, 
the  Coastal  Zone  Management  Porgram,  and  the  Uniform  Relocation 
Assistance  and  Real  Property  Acquisition  Policies  Act. 

Conclusion 

The  proposed  improvement  of  the  Central  Artery  has  been  advanced 
within  an  overall  process  which  has  involved  all  levels  of  govern- 
ment in  Massachusetts.   Initiation  of  the  project  by  the  City  of 
Boston  has  been  followed  by  procedural  steps  on  all  levels  to 
assure  that  the  proposal  will  be  thoroughly  examined  before  a 
final  decision  is  reached.   This  examination  will  of  necessity 
be  a  complex  and  lengthy  process,  involving  not  only  the  indivi- 
duals and  agencies  already  included,  but  many  more  by  the  time  a 
decision  is  made.   I  am  convinced  that  the  process  of  detailing 
the  implications  of  Artery  alternatives  is  essential,  and  that 
the  present  documents  are  substantial  evidence  of  problems  which 
must  be  dealt  with  by  proceeding  to  full-scale  environmental 
impact  analyses  for  both  the  Central  and  South  areas. 


JJezY   tru-J?/'  yours, 

(jSJLRROLL 
\COMMIS  SIGNER 


( 


SOUTH   AREA    PLANNING    STUDY 


Prepared  for  the  Massachusetts  Department  of  Public  Works 

by  the  Central  Transportation  Planning  Staff 

in  conjunction  with  the  MDPW  Central  Artery  Project  Staff 


March  1978 


This  report  has  been  prepared  pursuant  to  the 
requirements  of  the  Massachusetts  Action  Plan, 
with  the  financial  assistance  of  the  Federal 
Highway  Administration  and  the  Massachusetts 
Department  of  Public  Works. 


TABLE  OF  CONTENTS 


Chapter  I Summary  of  Findings 

I.  A  Purpose  Page  1 

I.B  The  Central  Artery  2 

I.C  The  Central  .Artery  Corridor  6 

I.D  Alternatives  to  Construction  in  the 

Central  Artery  Corridor  8 

.1.  Alignments  outside  the  Corridor  8 

.2  Analysis  of  Alignments  outside  the  Corridor    10 

I.E  The  Central  Artery  South  Portion: 

Description,  Service  Problems,  and 

Environmental  Impacts  11 

.1  Description  11 

.2  Transportation  Ser/ice  Problems  11 

. 3  Environmental  Impacts  12 

I.F  Alternatives  within  the  Central  Artery 

Corridor  13 

.1  Improvements  Along  the  Present  Alignment  13 

.2  Split  Alignment  Alternatives  14 

.3  Analysis  of  Alternatives  IS 

I.G  Conclusions   and  Recommendations  21 

Chaotar  II  The  South  Area 

II- A  Description  of  Existing  Facilities  25 

II. B  South  Area  System,  Characteristics  26 

.1  The  Dewey  Square  Tunnel  26 

-2  The  Approaches  to  the  Dewey  Square  Tunnel    31 

..3  Related  Problem  Areas  33 

II. C  South  Area  Traffic  Characteristics  35 

.1  Design  Deficiencies  35 

.2  Traffic  Characteristics  42 

II. D  Environmental  Conditions  59 

.1  Air  Quality  59 

.2  Noise  61 

.3  Water  Quality  64 

Chapter  III Alternatives  for  Improvement 

III. A  Past  Efforts  67 

.1  Alternatives  outside  the  Artery  Corridor  67 

.2  Corridor  Retention  74 

III.B  Alternatives  within  the  Present  Corridor  75 

.1  South  Area  Highway  Planning  Context  75 

.2  Derivation  of  Alternatives  79 

III.C  Alternatives  For  Further  Study  82 

.1  Relationship  to  other  potential  projects  82 

.2  Separability  of  the  South  Area  33 

.3  Feasible  Alternatives  83 

.4  Construction  Feasibility  10  2 


TABLE  OF  CONTENTS  (continued) 


III.D  Assessment  of  Impacts  105 

.1  Transportation  Operational  Improvements     105 

.2  Safety  112 
.3  Community  Impacts  113 
.4  Environmental  Impacts  116 
.5  Costs,  Construction  Duration  and  Disrup- 
tion 119 


Chaoter  IV 


Public  Participation 


IV. A 

rv.B 
rv.c 


Process 

Public  Involvement  Program 

Public  Comments  and  Responses 


121 
121 
122 


Chaoter  V 


Conclusions  and  Recommendations 


129 


Appendix  I 


Previous  Studies  Related  to  the  South 
Area  of  the  Artery  Corridor 


13'5 


C 


CHAPTER  1.     SUMMARY  OF  FINDINGS 


I, A  Purpose 


This  report  is  a  preliminary  overview  of 
engineering  and  environmental  impact  stud- 
ies completed  for  the  South  Area  of  Boston's 
proposed  Central  Artery  project  and  is  the 
basis  for  detailed  future  engineering,  en- 
vironmental and  related  studies. 

In  the  report,  the  South  Area  is  de- 
scribed in  terms  of  existing  facilities, 
system  characteristcs,  traffic  character- 
istics, and  environmental  conditions.   Then, 
alternatives  for  imorovement  are  oresented 
both  in  terms  of  possible  construction  ex- 
ternal to  the  Central  Artery  Corridor  and 
in  tearms  of  potential  actions  solely  with- 
in the  South  of  the  Artery  Corridor.  Sub- 
sequently, alternatives  outside  of  the 
Central  Artery  Corridor  are  eliminated  from 
further  consideration  because  of  construc- 
tion, traffic,  and/or  environmental  pro- 
blems.  Attention  is  then  devoted  to  con- 
struction alternatives  solely  within  the 
South  Area  of  the  Central  Artery  Corridor. i- 

Nine  construction  options  are  described  and 
evaluated,  and  seven  are  proposed  for  fur- 
ther study.   Finally,  general  conclu- 
sions and  recommendations  are  reached  re- 
garding potential  construction  in  the 
South  Area.   Throughout  this  report,  re- 
sults are  utilized  from  various  analyses 
performed  by  the  Massachusetts  Department 
of  Public  Works  (D.P.W.)  and  other  organ- 
izations. 


1  Construction  options  for  the  South  and 
North  Sections  of  the  Central  Artery 
Corridor  are  taken  up  in  separate  reports 


THE  CENTRAL  ARTERY 

The  Central  Artery  (1-93)  is  a  multilane 
freeway  traversing  the  Boston  core  area. 
It  stretches  in  a  generally  southerly 
direction  from  the  junction  of  1-93  and  the 
Mystic  River  Bridge  approach  in  Charlestown 
north  of  downtown  Boston,  over  the  Charles 
River,  through  downtown  Boston,  and  then 
south  to  the  interchange  between  Massa- 
chusetts Avenue  and  the  Southeast  Express- 
way just  south  of  Boston's  central  business 
district.   It  is  about  three  miles  long. 
Figure  1  shows  the  Central  Artery  in  the 
context  of  the  regional  Boston  express 
highway  system. 

The  Central  Artery  connects  with  a  number 
of  arterial  highways  along  its  length.   As 
seen  in  Figure  2,  just  south  of  the  Charles 
River  it  connects  with  the  McGrath/O'Brien 
Highway  and  Storrow  Drive  which  provide 
service  to  the  northwest  and  west  respec- 
tively.  In- the  downtown  area  itself,  the 
Central  Artery  connects  with  the  Callahan 
and  Sumner  tunnels  which  provide  service  to 
and  from  East  Boston  and  Logan  Airport. 
In  downtown  Boston,  the  Central  Artery  has 
connections  with  many  downtown  streets . 
South  of  downtown,  it  has  a  large  inter- 
change with  the  eastern  terminus  of  the 
Massachusetts  Turnpike. 

Through  its  various  interconnections, 
the  Central  Artery  provides  access  tc  a 
number  of  distinct  districts  of  the 
Boston  central  area.   Included  in  the 
areas  served  are  the  financial  district, 
the  retail  shopping  area,  the  office 
district,  the  Government  Center,  the 
industrial  and  seaport  areas  in  South 
Boston  and  Charlestown,  the  industrial 
areas  of  East  Cambridge  and  Charlestown, 
the  North  End,  the  North  Station  area, 
the  Waterfront,  Chinatown,  the  South 
End,  West  End,  South  Cove  and  South 
Boston  residential  areas. 


When  the  Central  Artery  was  constructed 
in  the  1950 's,  it  was  conceived  as  the 
most  important  link  of  the  full  express- 
way network  proposed  in  the  194  8  master 
highway  plan  for  the  Boston  area. 


REGIONAL   NETWORK 


Figure  1 


Because  the  Central  Artery  was  built 
before  the  Interstate  highway  program, 
it  was  built  without  Federal  assistance, 
and  its  capacity  and  design  were  re- 
stricted.  As  a  result  of  insufficient 


capacity  -  generally  the  Central  Artery 
is  a  six  lane  facility  -  it  acts  as  a 
bottleneck  both  to  the  north  and  to  the 
south.   At  its  northern  terminus,  five 
lanes  from  1-93  merge  with  five  lanes 
from  the  Mystic  River  Bridge  to  form  a 
facility  of  only  six   lanes  across  the 
Charles  River.   At  the  south  end  of  the 
Central  Artery,   six  lanes  from  the 
Southeast  Expressway  and  six   lanes 
from  the  Massachusetts  Turnpike  also 
merge  together  in  a  facility  only  having 
six  lanes.   Traffic  going  from  and  to 
other  major  roads  along  the  Central  Artery 
compounds  the  problems  caused  by  the 
Artery's  insufficient  capacity. 

From  a  design  point  of  view,  the  Central 
Artery  is  also  inadequate  by  modern 
standards.   In  its  three  mile  length,  it 
has  no  breakdown  lanes.   It  also  has  a 
total  of  42  ramps,  25  for  local  service, 
and  17  for  connections  to  expressways, 
the  Mystic  River  Bridge,  and  the  tunnels. 
Because  of  the  lack  of  breakdown  lanes, 
any  traffic  incident  in  either  roadway, 
even  a  stalled  vehicle,  diminishes  ef- 
fective capacity  in  the  'direction  affected  by 
at  least  one  third.  Because  of  the  original 
design,  the  ramps  are  also  inadequate,  having 
insufficient  speed  change  lanes  and  sight- 
lines.   This  results  in  severe  satety 
hazards  and  further  diminishes  the  ef- 
fective capacity  of  the  Central  Artery 
roadway.   In  addition,  the  closely 
spaced  ramps  cause  conflicts  with  through 
traffic.   Some  ramps  use  surface  streets 
for  through  expressway  traffic  which 
conflicts  with  surface  traffic  and  pedes- 
trians.  Finally,  much  of  the  Central 
Artery  is  an  unsightly  elevated  structure 
which  is  generally  regarded  as  a  blighting 
influence  on  downtown  Boston  with  severe 
aesthetic  and  other  negative  environmental 
impacts . 

In  addition  to  these  problems,  it  is  apparent 
that  the  decks  of  the  Artery  must  be 
replaced  by  1984-1989.   These  concerns 
have  led  to  several  Central  Artery 
studies,  including  the  current  ones,  all 
developed  to  determine  how  best  to 
address  the  deficiencies  of  the  facil- 
ity. 


CENTRAL  ARTERY 


Figure    2 


THE  CENTRAL  ARTERY  CORRIDOR 

For  purposes  of  planning,  the  Central  Ar- 
tery Corridor  has  been  defined  as  the  area 
stretching  roughly  half  a  mile  on  either 
side  of  the  Central  Artery  roadway,  and  a 
similar  distance  beyond  each  end  of  the 
Artery.   As -such,  the  corridor  encompasses 
the  entire  area  that  is  likely  to  be 
physically  affected  by  potential  Central 
Artery  reconstruction.   The  area  of  the 
corridor  includes  about  half  of  Charlestown, 
most  of  downtown  Boston,  and  portions  of 
the  South  End  and  the  industrial  area  of 
South  Boston. 

Figure  3  shows  the  three  designated  sub- 
areas  of  the  Central  Artery  Corridor: 
North,  Central,  and  South.   These  areas 
have  been  defined  to  help  plan  and 
advance  Central  Artery  improvements  in 
sub-sections  that  are  both  analytically 
manageable  and  financially  feasible. 
From  an  analysis  point  of  view,  this 
definition  of  subareas  is  helpful  be- 
cause it  allows  greater  focus  on  al- 
ternatives and  their  impacts.   From  a 
financial  point  of  view,  this  provides  a 
basis  for  realistic  assessment  of  the 
probable  sequencing  of  funding  and  con- 
struction timing  for  potential  project 
elements.   It  also  allows  potential 
improvements  to  be  made  on  varying  time 
schedules  and  expenditure  levels.  Geograph- 
ically, the  Artery  also  divides  naturally 
into  North,  Central,  and  South  sections  with 
largely  separable  functions  and  physical 
features.  Thus  potential  improvements  to  the 
different  sections,  while  fitting  together 
in  a  unified  structure,  nonetheless  have 
individual,  benefits  and  can  be  constructed 
independent  of  one  another. 


ARTERY  CORRIDOR  STUDY  AREAS 


Figtire  3 


ALTERNATIVES  TO  CONSTRUCTION  IN  THE  CENTRAL 
ARTERY  CORRIDOR 

Several  alternatives  to  construction  in  the 
Central  Artery  Corridor  have  been  explored 
in  various  studies.   These  have  been  ex- 
tensively reexamined  and  found  to  be  inad- 
equate to  solve  the  various  operational  and 
safety  problems  of  the  Artery.   These 
alternatives  are  described  below  and  ill- 
ustrated in  Figure  4.   All  have  been  dropped 
from  further  consideration. 

ALIGNMENTS  OUTSTDE  THE  CORRIDOR 

1.  The  Inner  Belt.   This  option  was  ruled 
out  bv  governor  Sargent  in  1971  for  these 
reasons:  residential  takings  and  reloca- 
tion requirements,  comirunity  disruption, 
commtinity  protest,  technical  questions  re- 
garding ability  to  accommodate  projected 
traffic  volumes,  and  generation  of  additional 
traffic  for  the  Boston  core  area. 

2.  Outer  Harbor  Crossings.  This  proposal 
for  a  highway  from  Quincy  to  Winthop  via 
the  harbor  islands  and  a  combination  of 
bridges  and  causeways  was  ruled  out 
because  of  environmental  impacts,  intru- 
sion into  the  flight  paths  of  Logan  Air- 
port, inadequate  provisions  for  connec- 
tions to  other  expressways,  and  lack  of 
downtown  collection  and  distribution 
relief. 

3.  Chelsea/East  Boston  Bypass  -  This 
option  from  1-93  North  via  Chelsea  and 
East  Boston  to  a  tunnel  under  the  harbor 
was  ruled  out,  among  other  reasons,  be- 
cause of  residential  takings   and  reloca- 
tion requirements,  community  disruption, 
impacts  on  shipping  in  Chelsea  Creek,  the 
necessity  of  a  tunnel  under  East  Boston, 
and  partial  dependence  on  1-95  in  Lynn 
(dropped  in  1972)  and  the  proposed  1-95 
Relocated  in  Revere  (dropped  in  1972) . 

The  tiinnel  under  the  harbor  is  the  proposed 
Third  Harbor  Crossing,  a  part  of  the 
projected  ultimate  regional  expressway 
network.   It  is  considered  in  this  report 
as  it  relates  to  South  Area  studies. 

4.  Pier  Tip  Bypass  -  This  alternative 
would  consist  of  a  highway  from  Charles- 
town  to  South  Boston  via  a  harbor  tunnel 


A.INNEH   BELT 

B.OUTEfl    HANSON   CMOSSINO 

C.  CHELSEA-  EAST  BOSTOM  9V 

aP1ER-TI^  ALIGNMENT 

E  CnOSS-BOSTON   TUNNEL 


ALTERNATIVES   TO  THE  ARTERY   CORRIDOR 


Figure    4 


along  the  tips  of  the  downtown  piers.   It 
has  been  eliminated  from  further  ronsider- 
ation  because  of  the  lack  of  necessary 
connections  with  the  Sumner-Callahan 
tunnels,  steep  grades,  and  difficult 
design  and  engineering  problems  including 
ventilation  and  interconnections  with  other 
expressways. 

5.   Cross  Boston  Tunnel  -  This  option 
includes  a  tunnel  from  Charlestown  to  South 
Station  under  Beacon  Hill,  the  Boston 
Common,  and  the  downtown  Boston  retail  area. 
It  was  ruled  out  because  of  technical 
infeasibility ,  questions  of  grades  and 
ventilation,  lack  of  interconnections  with 
expressways,  failure  to  connect  with  the 
Sumner-Callahan  tunnels,  and  lack  of  ■ 
collection/distribution  services. 


Analysis  of  Alignments  Outside  the  Corridor 

Analysis  of  solutions  to  the  Central  Artery 
problems  by  construction  outside-  the  corridor 
yields  several  major  conclusions.   First, 
technically  and  socially  acceptable  al- 
ternative alignments  to  provide  for  Central 
Artery  functions  cannot  be  found  outside 
of  the  corridor.   Second,  the  present 
corridor  is  the  only  one  that  can  effec- 
tively connect  with  all  of  the  expressways 
and  tunnels,  and  also  serve  downtown 
collection/distribution  needs. 

For  these  reasons,  and  because  extensive 
deck  repairs  must  be  made  in  the  elevated 
portions  of  the  present  Central  Artery 
regardless  of  whether  other  improvements 
are  undertaken,  it  is  appropriate  that 
specific  alternative  improvement  projects 
be  developed  for  the  Central  Artery  corridor. 
In  accordance  with  normal  highway  planning 
practice,  the  alternatives  include  the  "no- 
build"  option,  which  would,  as  a  minimiom, 
provide  for  necessary  bridge  deck  replace- 
ment- 


I . E         THE  CENTRAL  ARTERY  SOUTH  PORTION:   DE- 
SCRIPTION, SERVICE  PROBLEMS,  AND  ENVIRON- 
MENTAL IiMPACTS 

I.E.I      Description 

The  south  portion  of  the  Central  Artery 
lies  on  the  south  side  of  the  downtown 
Boston  area,  and  includes  the  Dewey  Square 
(or  South  Station)  Tunnel  and  the  elevated 
portion  of  the  roadway  leading  from  the 
tunnel  into  the  Southeast  Expressway.   The 
major  intersection  in  the  south  segment  of 
the  Central  Artery  is  the  complex  inter- 
change with  the  terminus  of  the  Massachu-; 
setts  Turnpike  (Interstate  Route  1-90) . 
In  addition,  there  are  many  other  access 
ramps  to  local  streets  and  arterials  through- 
out the  length  of  this  portion  of  the  Artery. 
South  of  the  Turnpike  interchange,  frontage 
roads  provide  access  to  and  from  the 
Artery  as  well  as  service  to  industrial 
areas.   Areas  over  the  Dewey  Square  Tunnel 
include  a  surface  arterial,  which  becomes 
parallel  one-way  streets  north  of  Dewey 
Square. 

I.E. 2      Transportation  Service  Problems 

The  south  portion  of  the  Central  Artery 
has  a  number  of  service  problems  resulting 
from  inadequate  capacity  and  restricted 
design.   The  major  capacity  problem  is 
caused  by  the  merging  of  the  Massachusetts 
Turnpike  and  the  Southeast  Expressway  into 
the  Artery.   This  capacity  problem  is  seen 
most  strikingly  in  the  Dewey  Square  Tunnel, 
in  its  approaches  to  the  south,  and  on  the 
surrounding  neighborhood  streets.   The 
tunnel  itself  was  designed  for  an  average 
daily  traffic  load  of  77,000  vehicles.   It 
is  presently  carrying  approximately  135,000 
vehicles  daily.   With  this  situation, 
traffic  is  severely  congested  in  the  tunnel, 
operating  under  forced  flow  conditions 
during  peak  periods,  and  often  during  off- 
peak  periods  as  well.   The  capacity  problem 
is  also  seen  in  the  form  of  substantial 
queuing  in  the  northbound  lanes  south  of 
the  Dewey  Square  Tunnel,  mostly  during 
the  morning  peak.   Morning  queues  are 
average  about  a  mile  and  one-half  in  length, 
and  their  length  and  duration  have  grown 


over  the  years.   Finally,  the  capacity 
problem  of  the  Dewey  Square  Tunnel-  is 
exacerbated  by  inbound  morning  traffic 
which  uses  local  streets  to  avoid  the 
congestion  of  the  tunnel.  This  situation 
is  reversed  in  the  evening. 

The  problem  of  insufficient  lanes  in  the 
South  Area  portion  of  the  Central  Artery  is 
compounded  by  the  design  of  the  facility, 
particularly  in  the  Dewey  Square  Tunnel. 
In  the  tunnel  there  are  substandard  sight- 
lines  and  excessive  curves  and  grades. 
Throughout  the  South  Section  of  the  Artery 
there  is  a  lack  of  adequate  acceleration, 
deceleration,  and  breakdown  lanes.   Ramps 
are  numerous  and  poorly  placed,  allowing 
insufficient  distances  for  merging  and 
weaving.   All  of  these  problems  have  acted 
to  diminish  capacity  further,  and  have 
contributed  to  an  accident  experience  that 
is  far  above  average.   During  1975,  the 
South  Section  of  the  Central  Artery  exper- 
ienced 449  reported  accidents.   On  a  ve- 
hicle mile  basis ,  this  is  about  three  times 
the  national  average  for  urban  expressways . 

Finally,  the  decks  of  the  elevated  portion  of 
the  Central  Artery  South  Section  are  ex- 
periencing rapid  deterioration  and  will  re- 
quire major  repairs  and/or  replacement  in 
the  near  future.   Emergency  maintenance  con- 
tracts have  already  been  let  in  attempts  to 
reduce  the  rate  of  deck  deterioration - 

Environmental  Impacts 

III      I  I  ■    — 

The  South  Section  of  the  Central  Artery  is 
associated  with  several  negative  impacts 
on  the  surrounding  areas.   South  of  the 
Dewey  Square  Tunnel,  the  facility  produces 
air  pollution,  dirt,  and  a  considerable 
amount  of  noise.   The  impact  is  particu- 
larly felt  in  Chinatown  adjacent  to  the 
interchange  between  the  Artery  and  the 
Massachusetts  Turnpike. 

In  the  Dewey  Square  Tunnel  area ,  the  Artery 
itself  does  not  cause  excessive  problems 
of  air  pollution  and  noise,  as  it  is  an 
enclosed  structure  with  ventilation  stacks. 
Noise  problems  are  caused  by  the  diverted 
traffic  using  local  streets  above  the 
Artery. 


Local  access  between  surface  streets  and 
the  Artery  is  inadequate  to  serve  down- 
town financial  and  commercial  area  needs. 
Access  locations  are  poorly  designed  in 
relation  to  emerging  land  use  patterns  and 
proposed  new  developmehts . 

Finally,  there  is  concern  that  exten- 
sive takings  and  environmental  damage 
occurred  to  the  surrounding  area  when  the 
Dewey  Square  Tunnel  was  constructed. 
There  is  a  strong  desire  that  in  any  new 
construction,  damage  in  the  area  be  amel- 
iorated rather  than  made  more  extensive. 

I.F        Alternatives  within  the  Central  Artery  Corridor 

Analysis  of  the  South  Area  of  the  Central 
Artery  corridor  has  led  to  two  main  groups 
of  alternatives  for  consideration.   The 
first  group  would  result  in  artery  traffic  in 
both  directions  continuing  to  follow  the 
present  alignment.   This  includes  the  no- 
build  alternative  and  alternatives  for  widen- 
ing or  double  decking  the  present  facility. 
The  second  group  would  result  in  a  split 
alignment  along  part  of  the  corridor,  with 
southbound  flow  on  the  present  alignment 
and  northbound  flow  on  one  of  two  potential 
new  alternative  alignments . 

I.F.I      Improvements  Along  the  Present  Alignment 

This  set  of  improvement  alternatives  centers 
on  the  existing  Dewey  Square  Tunnel. 

a.  No  Build  -  In  this  alternative  the  exist- 
ing facility  is  retained  and  modified  as 
necessary  to  accommodate  minor  improvements  for 
traffic  service  and  safety.   Traffic  capacity 
and  design  standards  would  remain  the  same  as 
they  are  today.   Deck  rebuilding  would  be 
required  south  of  the  Dewey  Square  Tunnel  be- 
cause the  decks  are  approaching  the  end  of 
their  useful  life. 

b.  Widening  of  the  Dewey  Square  Tunnel  - 
There  are  several  possibilities  for  widening 
the  Dewey  Square  Tunnel.   These  range  from 
the  addition  of  modest  improvements  to  the 
breakdown  and  speed  change  lanes  to  the  add- 
ition of  new  lanes  for  carrying  traffic.   If 
new  lanes  are  added,  they  must  be  located 


outside  the  existing  tunnel  on  one  or  t>otn 
sides  with  traffic  reallocated  between  exist- 
ing _  and  new  facilities.   Preliminary  analysis 
indicates  that  impacts  from  widening  the  pres- 
ent facility  are  extremely  damaging  to  adjacent 
communities  and  would  be  unacceptable  to  communi- 
ty leaders.   South  of  the  Dewey  Square  Tunnel  the 
viaduct  would  consist  of  three  lanes  in  each 
direction  with  a  shoulder  used  in  peak  hours  to 
accommodate  traffic  demand. 


c.   DouDle  Decking  tne  Present  Facility  - 
This  alternative  would  create  an  additional 
level  of  highway  in  a  viaduct  over  the  sur- 
face street  which  is  now  above  the  Dewey 
Square  Tunnel.   Capacity  in  the  South  Area 
would  be  increased,  and  the  tunnel  would  no 
longer  act  as  a  bottleneck  for  traffic,  be- 
cause the  Dewey  Square  Tunnel  would  only 
carry  southbound  traffic  and  the  new  facil- 
ity only  northbound  traffic.   This  alterna- 
tive would  also  be  unacceptable  to  commun- 
ities nearby  and  would  extend  this  blight- 
ing effect  of  the  elevated  structure  into  the 
Dewey  Square  area. 

Split  Alignment  Alternatives 

This  set  of  improvement  alternatives  centers 
on  use  of  both  an  improved  Dewey  Square  for 
southbound  traffic  and  a  new  facility  para- 
llel to  the  tunnel  for  northbound  traffic. 
This  new  facility  could  be  located  in  one  of 
two  locations  either  the  Fort  Point  Channel 
or  Atlantic  Avenue . 

a.   Fort  Point  Channel  Split  Alignment  - 
This  alternative  would  have  a  new  northbound 
tunnel  in  the  Fort  Point  Channel-parallel  to 
the  existing  Dewey  Square  Tunnel,  which  would 
serve  southbound  traffic .   The  new  tunnel 
would  begin  at  the  Turnpike  interchange  and 
extend  in  the  Channel  to  join  the  existing 
Central  Artery  right-of-way  in  the  vicinity 
of  the  Northern  Avenue  Bridge.  In  this  alter- 
native, the  Dewey  Square  Tunnel  would  no 
longer  be  a  constraint  on  traffic.   Design 
constraints  would  be  greatly  diminished  be- 
cause geometries  of  both  the  Dewey  Square 
Tunnel  and  the  new  pathway  would  be  modified 
to  meet  acceptable  design  standards.   This 
right-of-way  affords  ease  of  construction  be- 
cause of  the  relatively  clear  alignment,  without 
physical  restraints  imposed  by  existing  de- 
velopment. 


b«   Atlantic  Avenue  Split  Alignment  -   This 
alternative  is  similar  to  the  Fort  Point  Channel 
Split  alignment,  except  that  the  new  north- 
bound right-of-way  would  be  under  Atlantic 
Avenue.   The  new  tunnel  would  extend  from  the 
existing  right-of-way  under  the  rail  yards  and 
Atlantic  Avenue  and  rejoin  the  present  Artery 
near  Dewey  Square.  This  alternative  is  more 
difficult  to  construct  because  it  must  pass 
under  commuter  rail  and  AMTRAK  lines,  be 
constructed  under  an  existing  heavily  trav- 
elled street,  above  an  existing  rapid  tran- 
sit station  at  South  Station,  and  because 
of  a  narrow  right-of-way  at  Dewey  Square. 

The  latter  constraints  would  make  it  ex- 
tremely difficult,  if  not  impossible  to  add 
a  transit  connection  between  North  and  South 
Stations  as  part  of  the  Central  Area  recon- 
struction project,  should  it  be  undertaken. 

^•F.3      Analysis  of  Alternatives 

Preliminary  investigation  of  the  alterna- 
tives for  the  South  Area  has  indicated  that 
the  alternative  of  double  decking  the  present 
Dewey  Square  Tunnel  should  be  dropped  immed- 
iately because  of  severe  environmental  and 
economic  impacts  on  adjacent  properties, 
particularly  in  the  congested  areas  around 
the  Dewey  Square  Tunnel-   Additionally  the 
difficult  design  and  engineering  problems 
of  connecting  the  upper  roadway  to  other 
expressway  and  local  streets  requires  add- 
itional land  takings  and  would  therefore 
provide  additional  negative  impacts  on 
adjacent  properties. 

Because  the  present  Dewey  Square  Tunnel  is 
built  as  an  integral  structure  a  major  wid- 
ening would  require  the  construction  of  one 
or  more  parallel  tunnel  roadways  on  one  or 
more  sides  of  the  present  alignment.   Im- 
pacts of  maintaining  traffic  during  con- 
struction and  demolishing  buildings  along 
the  right-of-way  would  be  severe. 

Because  of  these  problems,  a  major  widening 
of  the  Dewey  Square  Tunnel  should  also  be 
dropped,  though  additional  analysis  will  be 
done  to  evaluate  and  document  more  fully 
the  extent  of  these  adverse  effects  prior 
to  undertaking  intensive  analysis  of  envir- 
onmental impacts  of  the  remaining  alternatives. 


There  may  be  some  alternatives  involving 
widening  of  lesser  proportions  which  may  be 
useful  in  developing  a  no-build  alternative 
that  offers  transportation  service  improve- 
ments beyond  simply  maintaining  the  existing 
situation.   These  will  be  evaluated  as 
variants  of  the  No-Build  Alternative. 
Both  of  the  Split  Alignment  Alternatives 
have  been  retained  for  further  study. 
However,  both  alternatives  (Fort  Point 
Channel  and  Atlantic  Avenue)  afford  similar 
transportation  service  improvements  for 
the  South  Area.   In  both  alternatives  a 
new  right-of-way  for  northbound  traffic 
is  proposed  to  overcome  the  right-of-way  con- 
straints present  in  alternatives  which  are 
restricted  to  the  Dewey  Square  Tunnel.   The 
Atlantic  Avenue  Alternative  is  a  variation 
on  the  split  alignment  in  the  Fort  Point 
Channel  and  is  rather  recent  in  origin  and 
has  resulted  from  review  of  widening  alter- 
natives.  Therefore  it  has  been  retained  to 
allow  further  detailing.   For  purpose  of 
this  discussion,  the  Atlantic  Avenue  align- 
ment is  included  as  a  variation  of  the  Fort 
Point  Channel  Split  Alignment. 

There  are  two  basic  types  of  alterhatives- 
the  No  Build  and  the  Split  Alignment-with 
variations  to  each,  as  discussed  above  . 
The  two  basic  alternatives  must  be 
examined  in  relation  to  other  potential 
transportation  improvements  which  affect  the 
South  Area.   These  are  the  proposed  improve- 
ments in  the  Central  Area  of  the  Artery  corr- 
idor and  the  proposed  third  harbor  tunnel 
between  downtown  and  Logan  Airport-   Proposals 
for  a  third  harbor  tunnel  include  two  op- 
tions -  a  special  purpose  tunnel  limited  to 
buses,  taxis,  limousines  and  emergency  ve- 
hicles ,  and  a  general  purpose  tunnel  open  to 
all  traffic.   In  either  case,  the  third 
harbor  tunnel  would  serve  only  Logan  Airport. 

These  potential  projects  outside  of  the  South 
Area  would  impact  South  Area  alternatives 
in  several  ways.   Potential  improvements  in 
the  Central  Area  of  the  Artery  corridor  would 
influence  at  least  the  design  of  the  connec- 
tion between  the  South  and  Central  Areas 
and  the  travel  time  benefits  of  both  areas. 
Similarly,  the  third  harbor  tunnel  would 
affect  the  design  of  the  South  Area  alterna- 
tives if  it  shared  an  alignment  in  the  Fort 


Point  Channel.   The  design  implications 
differ  depending  on  whether  the  tunnel  is 
for  special  or  general  purposes. 


In  sum,  the  two  basi 
Area  -  No  Build  and 
be   analyzed  with  a 
permutations  of  the 
without  the  Central 
with  and  without  a  t 
either  special   or  g 
gether  this  comes  to 
natives  as  shown  in 
initial  alternatives 
described  below. 


c  options  for  the  South 
Split  Alignment  -  must 
11  the  combinations  and 
other  projects:  with  and 
Area  improvements ,  and 
hird  harbor  crossing 
eneral  purpose.   Alto- 

a  total  of  nine  alter- 
Figure  5 .   The  nine 

for  analysis  are 


Figure  5  :  South  Area  Alternatives 


Without 

3rd  H.C. 

With  3rd  Harbor  Crossing 

Special 
Purpose 

General 

PUTDOSe 

NO  BUILD 

Alt.  1 

Alt.  2 

Alt.  3 

SPLIT  AT.TGNMENT 
WITHOUT  CENTRAL 
AREA 

Alt.  4 

Alt.  5  • 

Alt.  6 

SPLIT  ALIGNMENT 
WITH  CENTRAL 
AREA 

Alt.  7 

Alt.  3 

Alt.  9 

Alternative  1:   The  No  Build  Alternative 


The  No  Build  Alternative  has  been  devel- 
oped to  explore  the  possibility  of  retain- 
ing the  existing  facility  with  some  modific- 
ations to  prolong  its  useful  life.   South 
of  the  Dewey  Square  Tunnel ,  the  Artery  decks 
need  replacement  in  the  near  future  if  no 
other  improvements  are  made.   In  undertaking 
this  work,  one  lane  of  decking  would  be  done 
at  a  time.   Traffic  would  be  maintained,  but 
during  construction  capacity  on  the  roadway 
would  be  reduced  by  approximately  one-third. 
Some  frontage  road  capacity  could  be  used 
during  construction. 


In  the  Dewey  Square  Tunnel  area,  modifica- 
tion could  range  from  minor  changes  to  the 
tunnel  to  selecting  widening  to  improve 
traffic  operations.   Alternative  1  can 
be  constructed  with  or  without  the  pro- 
posed Central  Area  project  in  the  Artery 
corridor. 

Alternative  2  -  The  No  Build  Alternative 
with  a  Special  Purpose  Third  Harbor  Tunnel 

Alternative  2  is  similar  to  Alternative 
1  in  all  respects,  except  for  a  special 
purpose  tnird  harbor  tunnel.   The  con- 
nection between  the  South  Area  express- 
way facilities  and  the  proposed  tunnel 
would  be  made  at  the  interchange  between 
the  Southeast  Expressway  and  the  Turnpike. 
The  two-way  special  purpose  tunnel  would 
be  located  in  the  Fort  Point  Channel.   The 
tunnel  would  be  built  as  a  separate  proj- 
ect, independent  of  improvements  for  the 
South  Area  of  the  Artery. 

While  the  special  purpose  tunnel  would 
provide  improved  service  to  limited  types 
of  vehicles,  it  would  primarily  serve  only 
those  vehicles  approaching  i.t  from  the 
'Arest  and  south.   From  other  directions 
5uch  vehicles  would  have  to  travel  the 
full  length  of  the  Artery  to  reach  the 
tunnel  approaches .   It  would  have  the 
salutary  effect  of  removing  vehicles  from 
the  Central  Area  of  the  corridor,  to  the 
extent  that  the  service  provided  by  buses 
or  other  multiple  occupancy  vehicles  could 
attract  more  ridership. 

Alternative  3  -  The  No  Build  Alternative 
with  a  General  Purpose  Third  Harbor  Tunnel 

This  alternative  is  identical  to  Alter- 
native 2  with  the  added  feature  of  divert- 
ing general  traffic  from  the  existing 
Artery  to  the  third  harbor  crossing.   As 
in  Alternative  2 ,  the  proposed  harbor 
tunnel  would  be  built  in  the  Fort  Point 
Channel  with  its  interchange  at  the  junc- 
tion of  the  Southeast  Expressway  and  the 
Massachusetts  Turnpike. 


Alternative  4  -  Split  Alignment  without 
the  Central  Area  Project 

In  this  alternative,  the  South  Area  of 
the  Artery  is  reconstructed  but  no  major 
improvements  are  made  to  the  Central 
section.   The  reconstruction  of  the  South 
Area  would  include  a  new  northbound  tunnel 
of  three  lanes,  with  shoulders  used  in  peark 
hours  to  accomodate  traffic  demand.   It 
would  be  located  under  Atlantic  Avenue  or 
in  the  Fort  Point  Channel  and  would  be 
connected  to  the  elevated  Central  section 
in  the  vicinity  of  Northern  Avenue.  The 
Dewey  Square  Tunnel  would  be  retained  for 
southbound  movement,  but  could  be  modified 
for  better  geometries  and  lane  configura- 
tion.  It  would  include  three  southbound 
lanes,  with  shoulders  used  in  peak  hours  to 
accomodate  traffic  demand.   Local  street 
connections  would  be  modified  to  provide 
improved  service  between  the  expressways 
and  the  surface  street  network  in  the 
South  Boston  seaport  areas ,  South  Station 
and  the  proposed  transportation  terminal, 
and  the  retail  and  financial  districts  of 
Downtown  Boston. 

Alternative  5  -  Split  Alignment  without 
the  Central  Area  Project  and  with  a  Special 
Purpose  Third  Harbor  Tunnel 

This  alternative  is  similar  to  Alternative 
4,  with  the  addition  of  the  special  pur- 
pose tunnel  to  and  from  the  airport. 
Connection  to  and  from  the  harbor  tunnel 
would  be  made  via  the  relocated  northbound 
roadway  of  the  split  alignment. 

This  alternative  would  allow  construction 
of  the  northbound  roadway  and  the  special 
purpose  tunnel  to  be  undertaken  without 
disruption  to  existing  Artery  traffic. 

Alternative  6  -  Split  Alignment  without 
the  Central  Area  Project  and  with  a  General 
Purpose  Third  Harbor  Tunnel 

This  alternative  is  identical  to  Alternative 
5  with  the  exception  of  general  purpose 
traffic  utilizing  the  proposed  harbor  tunnel 


Alternative  7  -  Split  Alignment  with  the 
Central  Area  Project 

Alternative  7  provides  for  a  major  im- 
provement in  the  South  Area  with  the  con- 
struction of  a  new  northbound  roadway 
either  under  Atlantic  Avenue  or  in  the  Fort 
Point  Channel.   The  existing  Dewey  Square 
Tunnel  would  then  become  one-way  south 
bound.   Both  the  relocated  northbound 
roadway  and  the  improved  southbound  road- 
way would  be  linked  to  a  reconstructed 
Central  Area.   This  connection,  located 
near  the  Northern  Avenue  Bridge,  would  be 
underground.   Revisions  to  the  existing 
ramps  in  the  Dewey  Square  Tunnel  would  be 
necessary  to  provide  appropriate  con- 
nections with  local  streets.   New  con- 
nections to  local  streets  would  be  pro- 
vided from  the  new  northbound  tunnel  to 
local  streets  including  Northern  Avenue, 
Kneeland  Street/Atlantic  Avenue,  Broadway 
as  well  as  access  to  and  from  the  proposed 
transportation  terminal  at  South  Station. 
Additional  connections  could  be  provided 
at  a  later  date  to  the  proposed  tiiird 
harbor  tunnel  if  that  facility  is  to  be, 
constructed. 

In  this  alternative,  construction  of  the 
northbound  roadway  would  be  undertaken 
without  serious  disruption  to  existing 
Arterv  traffic.   After  completion  of _ the 
tunnel,  connections  to  roadways  on  either 
end  of  the  Dewey  Square  Tunnel  could  be 
reconstructed  without  excessive  traffic 
disruption.   As  northbound  traffic  would 
be  in  the  new  alignment,  southbound 
traffic  can  be  detoured  berween  the 
existing  north  and  south  bound  lanes  of 
the  Dewey  Square  Tunnel  during  construc- 
tion. 

The  proposed  North  Station-South  Station 
rail  connection,  which  is  part  of  the 
Central  Area  project,  is  not  a  part  of 
any  alternative  for  the  South  Area, 
except  immediately  behind  South  Station. 


Alternative  8  -  Split  Alignment  with  the 
Central  Area  Proiect  and  a  Special  Purpose 
Third  Harbor  TurmeT  

Alternative  8  is  similar  to  Alternative  7 
and  includes  a  special  purpose  third 
harbor  tunnel  to  and  from  the  a.irport.   The 
tunnel  would  connect  with  the  South  Area 
project  at  the  mouth  of  the  Fort  Point 
Channel,  and  would  link  to  the  new  north- 
bound roadway  and  the  existing  Dewey  Square 
Tunnel.   Local  street  connections  would  be 
provided  as  in  Alternative  7. 

As  in  Alternative  7,  construction  of  the 
nortlibound  roadway  and  the  special  pur- 
pose tunnel  would  be  undertaken  without 
serious  disruption  to  traffic  on  the 
1-93  northbound  roadway.   Construction 
phasing  of  this  alternative  would  be 
closely  related  with  the  Central  Area 
phasing. 

Alternative  9  -  Split  Alignment  with  the 
Central  Area  Project  and  a  General  Pur- 
pose Third  Harbor  Tunnel 

Alternative  9  is  identical  -to  Alternative 
8  except  that  the  third  harbor  tunnel  is  a 
general  purpose  facility  to  and  from  the 
airport.   The  tunnel  would  connect  with 
the  South  project  at  the  mouth  of  the  Fort 
Point  Channel  and  lead  to  the  airport  access 
road.   Direct  connections  to  and  from  the 
North  Shore  would  not  be  provided  in  this 
option.   However,  there  would  be  direct 
connections  for  traffic  from  the  South- 
east Expressway  and  the  Massachusetts 
Turnpike  into  the  harbor  t-unnel.   Access 
from  the  north  and  northwest  to  the  new 
tunnel  would  be  less  direct;  this  traffic 
would  continue  to  use  the  present  harbor 
tunnels  for  access  to  and  from  the  airport. 

I.G         CONCLUSIONS  AND  RECOMMENDATIONS 

Severe  capacity  and  safety  problems  and 
design  deficiencies  exist  in  the  South 
Area  portion  of  the  Central  Artery.   In 
the  near  future  it  will  at  a  minimum  be 
necessary  that  deck  repairs  be  made  to 
the  existing  facility  in  order  to  keep  it 
operating.   At  this  point,  however,  it 
is  appropriate  that  alternative  actions 
be  analyzed  that  address  both  the  mainte- 


nance  of  its  functional  integrity,  and  also 
potential  means  to  resolve  its  basic  capacity, 
design,  and  environmental  deficiencies. 

Initial  analysis  has  shown  that  there  are  no 
feasible  construction  alternatives  outside 
of  the  Central  Artery  corridor  that  can  re- 
solve traffic  problems  within  the  corridor. 
Also,  transit  options  cannot  solve  the  corr- 
idor highway  problem.   In  the  South  Area, 
there  are  two  basic  alternatives  to  be  con- 
sidered:  No  Build  and  Split  Alignment.   Each 
of  these  has  been  analyzed  in  combination 
with  potential  Central  Area  improvements  and 
alternatives  for  a  Third  Harbor  Tunnel.   A 
total  of  9  alternatives  was  studied,  three 
of  which  directly  address  problems  of  the 
South  Area.   These  are  alternatives  1,  4  and 
7 ,  and  they  should  be  carried  into  further 
environmental  and  engineering  analysis.   In 
subsequent  studies  of  these  alternatives, 
they  will  be  designed  to  accomodate  the  poten- 
tial Third  Harbor  Tunnel  as  a  separately  built, 
but  physically  connected  future  project. 
Alternatives  2  and  3,  which  include  an  inde- 
pendent Third  Harbor  Tunnel,  preclude  South 
Area  improvements  on  a  split  alignment  and 
do  not  make  improvements  to  the  Artery  beyond 
those  in  Alternative  1.   For  these  reasons,  Al- 
ternatives 2  and  3  should  be  dropped  from 
further  consideration  as  potential  solutions 
for  the  South  Area  of  the  Antery.  Alternatives 
4  and  7  advance  the  Third  Harbor  Tunnel  be- 
cause they  could  later  be  connected  to  it. 
Alternatives  5,6,8  and  9  are  permutations  of 
Alternatives  4  and  7  which  include  a  Third  Har- 
bor Tunnel,  but  they  are  otherwise  identical 
to  Alternatives  4  and  7.   Of  these  six  alter- 
natives, 4  and  7  should  be  carried  forward  in- 
to further  engineering  and  environmental  analysis. 

It  should  be  noted  that  the  construction  of 
a  Third  Harbor  Tunnel  is  a  separate  project, 
serving  purposes  and  having  benefits  which  are 
different  from  the  reconstruction  of  the  South 
Area  of  the  Artery  Corridor.   The  alternatives 
which  have  been  developed  for  the  South  Area, 
and  which  should  be  carried  forward  (Alterna- 
tives 1,4,  and  7)  have  inherent  flexibility  to 
accomodate  a  potential  Third  Harbor  Tunnel 
while  meeting  South  Area  needs. 

Major  reconstruction  of  the  South  Area  of 
the  Artery  offers  the  possibility  of  implem- 
enting a  long-range  strategy  for  the  improve- 
ments of  the  economic  future  of  Downtown  Boston. 


The  Artery  affects  the  economic  vitality  of 
all  of  Downtown  Boston,  which  is  not  only  the 
core  of  the  metropolitan  area,  but  the  econ- 
moic  and  cultural  focus  of  the  New  England  re- 
gion.  The  proposed  improvement  alternatives 
affect  both  the  local  community  and  the  metro- 
politan and  New  England  regions  in  different  ways 

As  South  Area  planning  proceeds,  and  in 
accord  with  contemporary  transportation 
planning  practices,  detailed  studies  are 
appropriate  for  all  the  presently  re- 
tained South  Area  alternatives.   In 
particular,  the  following  tasks  require 
special  attention: . 

Transportation  Service 

Central  Artery  service 

Harbor  crossing  demand  and  airport 

service 

Local  street  service 

Capacity/ demand 

Design 

Overall  design  concept 

Structure  requirements 

Decking  requirements 

Tunnelling  requirements 

Ventilation  requirements 

Dangerous  cargo  handling 

Joint  rail  line  construction 

Existing  rail  line  service  req.uire- 

ments- 

Joint  development  opportunities 

Land  use  and  urban  design 

Impacts 

Economic  impacts  (regional  and  local) 
during  and  after  construction 
Social  impacts  (regional  and  local) 
during  and  after  construction 
Air,  noise,  and  water  quality  impacts 

Construction  Techniques  and  Phasing 
Safety  During  and  After  Construction 
Costs 

Other  tasks  for  specific  consideration  will 
become  clear  as  the  design  studies  them- 
selves are  planned  in  detail  and  subsequently 
undertaken. 


c 


CHAPTER  11=  THE  SOUTH  AREA 


II. A    DESCRIPTION  OF  THE  EXISTING  FACILITIES 


The   South  Area   is    the   key  highway   segment 
linking  the   Southeast   Expressway    (the 
only  major  highway   from  the   South   Shore 
Corridor)    and  Massachusetts   Turnpike 
from  the   Western   Corridor   to   downtown 
Boston   and  Logan  Airport.      Conflicts 
and   congestion   cause.d  by   the   mix  of 
local   downtown    traffic,    Logan  Airport 
traffic  and   intra-metropolitan    through 
traffic   reduce    the    level  of   service.      In 
addition,    the   number  of  on-and-off  ramps 
for  local   access    in    the   relatively   short 
distance   provides   poor  highway   geometries 
with  extremely   short  merging  and  weaving 
distances,    causing  traffic  bottlenecks 
and  unusually  high   incidence  of  accidents. 
Reduced  sight  distances   within    the   Dewey 
Square    Ttmnel    increase   hazards   on    this 
section. 

The   South  Area   includes   major  gateways   ta 
Boston    from  the   south. and  west.      All 
vehicular   and   transit  access    from  the 
south  passes   through   the   area;    vehicular 
access    from  the  west  via   the   Massachusetts 
Turnpike   also   enters    Downtown   through 
this   area.      The   geographic  constraints   on 
the   area  were    foinned  by   the   rivers    and 
harbor  which   still   define    the   setting 
and   affect   land  development  and 
transportation . 

Transportation   linkages   were   established 
early   in   the   corridor   to   the   south.      ^Vhen 
first  constructed   in   the   early   19th 
century,    they  were   built  over  bodies   of 
water  in  order  to   connect   to   the   downtown 
Boston  peninsula.      Bridges   and  roads 
built   in    the   early    18th   century  provided 
the    first  links   to   the   south   corridor 
and  gradually  became   major  highways. 
Until   construction  of  the   Southeast 
Expressway    (now   1-9  3) ,    major  highways 
connecting   the   Boston   Downtown   to   the 
South  Corridor  were  Washington   Street, 
Blue   Hill  Avenue,    Dorchester  Avenue, 
Summer  Street   and  Broadway. 


25 


Rail  lines  to  the  south  corridor  originally 
served  individual  termini,  but  were  con- 
solidated into  South  Station  in  1898. 
Certain  of  the  lines  to  the  west  were  also 
consolidated  into  South  Station  at  that 
time.   Upon  completion  of  the  Southeast 
Expressway  the  rail  lines  to  the  south 
corridor  were  abandoned  for  passenger 
service.   Although  the  Red  Line  rapid 
transit  serves  the  inner  portions  of  the 
corridor,  rail  transit  access  to  the  south 
corridor  was  not  provided  until  the  open- 
ing of  the  Quincy  Extension  in  1973. 

The  major  highway  to  the  south  -  the  South- 
east Expressway  -  was  built  as  an  extension 
of  the  elevated  portion  of  the  Central 
Artery  and  opened  in  19  59.   The  Dewey 
Square  Tunnel  was  a  major  portion  of  the 
construction  necessary  to  link  the  Central 
Artery  with  the  Expressway.   Some  years 
later,  in  1965,  the  Massachusetts  Turnpike 
from  the  west  was  added,  with  a  terminus  at 
the  Central  Artery  in  the  vicinity  of  South 
Station.   At  the  present  time  these  two 
roadways  form  the  major  feeders  into  Down- 
town in  the  South  Area.   Both  routes  provide 
local  service  into  neighborhoods  along  the 
fringe  of  Downtown. 

II. B.   SOUTH  AREA  SYSTEM  CHARACTERISTICS 
I I.B.I. The  Dewey  Square  Tunnel 


From  a  traffic  operations  point-of- 
view,  the  South  Area  has  a  major  inherent 
defect:   all  downtown-oriented  traffic 
to  and  from  the  South  must  use  the 
Dewey  Square  tunnel,  its  approaches 
from  the  South,  or  both.   For  traffic 
to  and  from  the  south,  avoiding  these 
two  facilities  is  almost  impossible.   The 
only  options  are  Dorchester  Avenue- 
Broadway,  Summer  Street,  or  Massachusetts 
Avenue.   Traffic  to  and  from  the  west 
has  similar  but  not  so  serious  traffic 
operations  problems.   Such  traffic  can 
use  Massachusetts  Avenue  to  avoid  the 
Artery  Corridor,  but  all  local  street 
bypass  routes  eventually  connect  with  the 
expressway  network  in  the  South  Area. 


SOUTH  AREA  STREET  SYSTEM 


Figure   6 


27 


The  cumulative  effect  of  these  problems 
produce  a  major  impact  on  safety, 
operations  and  transportation  service  in  the 
South  Area.   The  major  problem  is  the 
funnelling  of  traffic  from  expressways  and 
arterial  streets  between  the  Massachusetts 
Avenue  Interchange  and  the  Massachusetts 
Turnpike  into  the  6  lane  Dewey  Square 
Tunnel.   This  section  of  the  south  area 
is  inadequate  to  accommodate  the  heavy 
volume  of  traffic  at  acceptable  operating 
levels. 

For  example,  during  the  A.M.  peak,  traffic 
is  allowed  to  use  the  shoulder  of  the 
Southeast  Expressway.   Figure  7  presents 
the  lane  configuration  during  the  A.M. 
peak  for  inbound  traffic.   The  reverse 
situation  occurs  during  the  evening  peak. 

The  entire  problem  of  lane  imbalance  on 
the  Artery  is  magnified  because  of  right- 
of-way  limitations  within  the  immediate 
Corridor,  and  the  setting  in  a  highly 
developed  urban  area  where  transportation 
impacts  are  severe  and  alternatives  are 
limited. 

CEMTRAL  ARTERY 
(DEWEY  Sa  TUNNEL) 


MASS^  TURNPIKE 


-TUNNEL  APPROACHES 


MASS  AVE.  RAMPS 

S.E.  EXPRESSWAY 

(JN  PEAK  HOURS) 


SOUTH  AREA  EXPRESSWAY  LANES 


28 


Figure     7 


II.B.l.a,      Highway   and  Tiinnel   Problems 

The   South   Section   of   the   Central  Artery 
is   a   six  lane    facility  extending   from 
the   Massachusetts   Avenue    Interchange    to 
approximately   the  Northern   Avenue   on-ramp. 
The  Section   is    split   approximately   in 
half  with   50%   being  within   a   tunnel   and 
the  balance   on   viaduct.      Typically, 
each   roadway   is    40    feet   in  width,    having 
three    12-foot   lanes  with   2 -foot   lateral 
clearances   on  each   side.      There    are 
neither   shoulders   nor  breakdown  bays   on 
either   the   viaduct  or  within    the    tunnel. 
Auxiliary   speed   change   lanes   do   exist 
between   some   entrance   and  exit   ramps. 

The   2500'    6    lane   Dewey   Square   Tunnel   is 
the  only  expressway   link   in   the    South  Area 
between   the   highways    to    the   south   and   the 
Central  Artery   giving  access   to   Downtown 
and  the  north.      It  is   the   only  portion 
of   the  Artery   corridor  that   is    currently 
in    ttmnel.      The   Dewey   Square   Tunnel 
poses   the   major  constraints   on   the   South 
Area   in    terms   of   its   alignment,    safety 
and  capacity. 

Between    the   Massachusetts   Avenue    inter- 
change  and  the   North  portal  of  the 
tTonnel   there   are    seven   ramps   on   the 
north  bound   roadway   and  eight  on   the 
southbound  roadway.      Ramp   spacing  varies 
between    700+'    and   2500+'    on    the   northbound 
roadway,    and   770+'    and    1450+ '    on    the 
southbound  roadway.      Weaving  maneuvers 
are   generally  one-sided  weaves.      Because 
of  hazardous   operational   experiences    in 
the   past,    one    "off"    ramp   on    the   northbound 
tube   has  been  permanently   closed.      In 
addition,    during  the  morning  peak,    the 
Broadway    "on"    ramp   south   of   the    tunnel   is 
closed. 

Ramp  spacing  does  not  meet  minimum 
design  criteria.  This  item  is  particxilarly 
critical  to  operations  on  the  facility. 
Dxiring  peak  hours  this  results  in  vehicles  _ 
directly  entering  the  main  stream  of  traffi 
without"  the  value  of  acceleration  lanes  or, 
when  a  speed  change  lane  does  exist  between 
ramps,    it   is   of   insufficient   length. 


Critical  geometries  within  the  south  area  are 
located  within  the  tunnel.   In  general,  both 
design  and  average  highway  speed  on  the  Central 
Artery  is  50  MPH.  However,  within  the  tunnel, 
design  speed  varies  between  40  MPH  and  50  MPH. 
Superelevation  on  curves  within  the  tunnel 
varies  between  0.01  and  0.015  feet  per  foot. 

Not  only  are  traffic  operations  affected  by  the 
variance  in  design  speed  in  the  tunnel,  but 
also  safety.   The  40  MPH  design  section  is  part 
of  a  compounded  curve.   The  balance  of  this 
curve  has  50  MPH  design  speeds.   Therefore,  sight 
distance  along  the  high  speed  lane  of  the  south 
boxind  roadway  changes  along  the  curve  from  3  50+' 
to  275+' .   While  not  critical  in  peak  hours  this 
does  introduce  a  deficiency  in  safety  for  those 
off  peak  hours  when  speeds  approach  45-50  MPH. 
A  similar  situation  exists  in  the  outside  lane 
of  the  northbound  roadway  throughout  this  compound 
curve  section. 


^ 


R.1042' 
■L=33' 

FACE  OF    PORTAL 


R-IOOC 

L«142' 

D>5.7° 

R  -- 1500' 

L=119' 

0-3.8° 


DEWEY  SQUARE  TUNNEL  ALIGNMENT 


Figure   8 


■jn 


II.B.l.b    Tunnel  Connections  to  Surface  Streets 


The  original  plan  for  the  Dewey  Square 
Tunnel  relied  on  connections  with  down- 
town arterial s  to  provide  maximum  distri- 
bution and  collection  services.   In  some 
cases  the  surface  streets  have  been 
utilized  as  parallel  frontage  roads. 

North  of  Dewey  Square,  Atlantic  Avenue 
and  Purchase  Street  form  parallel 
frontage  roads  with  ramps  directly  to 
and  from  the  tunnel.   These  two  streets 
connect  with  other  local  streets,  but  are 
limited  in  their  usefulness  because  they 
extend  for  only  four  blocks  thro-ngh 
Downtown. 

South  of  D"ewey  Square  the  tunnel  is  on  an 
alignment  which  cuts  diagonally  across 
the  grid  pattern  of  surface  streets. 
As  a  result  the  surface  street  pattern 
is  ineffective  in  serving  the  collection 
and  distribution  functions  which  it  was 
intended  to  serve . 

Surface  street  changes  have  been  proposed 
over  the  years  to  improve  access  between 
the  tunnel  and  arterials,  and  to  better 
serve  new  development.   Closing  segments 
of  streets,  directional  changes,  widening 
specific  streets  and  new  alignments  for 
local  streets  have  all  been  considered. 
Yet  an  effective  overall  plan  continues 
to  depend  on  changes  to  the  deficiencies 
of  the  expressway  system. 

11--B.2        The  Approaches  to  the  Dewey  Square  Tunnel 


The  Artery  Corridor  immediately  south  of 
the  Dewey  Square  Tionnel  is  the  area  where 
the  effects  of  Dewey  Square  Txinnel  problems 
are  most  seriously  felt.   Much  of  the 
congestion  on  this  section  is  caused  by 
the  backup  from  the  Dewey  Square  Tunnel. 
In  addition,  this  area  is  critical  because 
of  the  connections  it  provides  between 
local  streets,  the  Southeast  Expressway, 
the  Massachusetts  Turnpike  and  Downtown. 

Problems  on  the  approaches  to  the  Dewey 
Square  Tunnel  can  be  divided  into  two 
parts:   those  associated  with  the 
Massachusetts  Tximpike  interchange  and 


31 


those  on  1-9  3  south  of  the  interchange, 
:.B.2.a   The  Massachusetts  Pike  Interchange 


The  Massachusetts  Turnpike,  built  in 
1965,  connected  to  the  Central  Artery 
in  the  vicinity  of  South  Station. 
The  interchange  was  constructed  on  former 
rail  yards,  and  property  was  taken  from 
Chinatown  to  complete  the  ramp 
connections.   Ramps  were  provided  to 
connect  to  the  Central  Artery  north 
and  south,  and  to  local  streets  such 
as  Kneeland  Street.   These  ramps  were 
located  in  constricted  space,  as  a 
result  optimum  geometric  design  could 
not  be  obtained. 

The  construction  of  this  interchange 
connects  with  the  Artery  at  the  South 
portal  of  the  Dewey  Square  Tunnel — 
the  main  constriction  of  the  South 
Area  of  the  Artery  Corridor.   Volumes 
on  the  Turnpike  in  this  area  now 
approach  60,000  per  day.   More  than 
half  of  the  traffic  is  destined  for 
the  northbound  roadway,  requiring 
motorists  to  use  the  Dewey  Square 
Tunnel  or  find  alternative  routes  on 
local  streets. 

Capacity  is  the  most  serious  problem 
at  the  Mass.  Pike  interchange.   Volumes 
have  been  growing  over  time,  and  at 
present,  the  congestion  in  this  area 
is  one  of  the  most  serious  in  the 
Artery  corridor.   The  capacity 
restriction  is  compounded  by  the  lack 
of  bypass  facilities  or  parallel  surface 
routes  for  spillover  traffic. 

,b   South  of  the  Mass.  Pike  Interchange 


The  roadway  section  between  the  Mass. 
Pike  interchange  and  the  Massachusetts 
Avenue/Southeast  Expressway  is  affected 
by  the  problems  of  the  Dewey  Square 
Timnel  and  the  Massachusetts  Turnpike 
Interchange.   Constructed  as  an 
elevated  viaduct  facility,  this  section 
is  constrained  by  the  lack  of  breakdown 
lanes,  acceleration  and  deceleration 
lanes  and  adequate  sight  lines.   As  a 


result  there  is  serious  congestion  during 
much  of  the  day.   Frontage  roads  have 
been  provided  but  they  are  not  continuous 
along  the  full  length  of  the  roadway.   They 
■  lead  to  surface  roadways  which  are  dis- 
continuous and  also  congested. 

Certain  of  the  surface  roadways  lead  into 
residential  neighborhoods,  resulting 
in  serious  traffic  disruption  to  the 
commiinities  along  the  South  Area  of  the 
Corridor.   Trucks — particularly  those 
carrying  dangerous  cargoes — leave  the 
Expressway  on  these  surface  streets 
and  travel  through  residential  streets 
and  the  edge  of  downtown,  further  adding 
to  traffic  operation  problems  and  congestion. 
At  the  Massachusetts  Avenue  interchange 
with  the  Artery  Northbound,  a  major  ramp 
enters  from  the  left,  compounding  the 
difficulties  on  the  Artery.   This  inter- 
change was  designed  for  ser-vice  to  the 
Inner  Belt,  which  is  no  longer  planned  for 
construction. 

II. B. 3   Related  Problem  Areas 


The  congestion  of  the  South  Area  of  the 
Artery  Corridor  causes  many  drivers  to 
attempt  to  avoid  this  section  of  the 
expressway  network.   They  do  so  by 
seeking  local  streets  which  do  not  have 
the  degree  of  congestion  which  is  usually 
present  on  the  Artery.   Limited  alternatives 
are  available  for  such  spillover  traffic. 
The  three  major  points  through  which  this 
spillover  traffic  must  pass  are:   (l)the 
Massachusetts  Avenue  interchange;  (2)  Summer 
Street  Bridge;  (3)  the  Broadway  Bridge. 

II.B.3.a   Massachusetts  Avenue  Interchange 

The  major  operational  problem  at  this 
interchange  is  the  connection  between  the 
Southeast  Expressway  and  the  local  arterial 
streets  in  the  South  End.   At  present,  the 
interchange  connects  directly  with 
directional  ramps  to  and  from  the  express- 
way to  Massachusetts  Avenue.   This 
interchange  was  designed  for  inter- 
state traffic  connecting  to  the  proposed 
Inner  Belt,  which  has  been  dropped  from 
further  consideration  for  construction. 

33 


It  would  have  served  traffic  between 
expressways  with  3  lanes  in  each 
direction;  these  lanes  now  provide  a 
means  for  motorists  to  avoid  the 
expressway  network  and  travel  through 
residential  streets  in  the  South  End 
as  alternative  means  of  reaching 
Downtown . 

I,B.3.b   Summer  Street  Bridge 

The  Summer  Street  Bridge  across  the 
Fort  Point  Channel  primarily  seirves 
access  between  Downtown  and  the 
industrial  and  residential  areas  of 
South  Boston.   Because  it  provides 
connections  between  several  of  the 
South  Corridor  major  arterials  and 
Downtown,  it  is  used  as  a  bypass 
route  for  traffic  attempting  to 
avoid  the  congestion  of  the  express- 
way network  ,  particularly  during 
peak  hours.   The  problems  with  it 
are  that  it  is  inadequate  from  a 
traffic  operations  viewpoint  and_ 
it  has  heavy  impacts  on  residential 
South  Boston.   It  is  not  an 
adequate  alternative  or  supplement 
to  the  Southeast  Expressway 
connections  in  the  south  corridor. 
With  expansion  of  the  port 
activities  in  the  South  Boston 
portion  of  the  Boston  Naval  Shipyard, 
and  the  expansion  of  associated 
truck  traffic,  the  potential  for 
additional  truck  traffic  will  add 
to  the  present  transportation 
problems  of  Summer  Street. 

II.B.3.C   Broadway  Bridge 

The  Broadway  Bridge  is  a  part  of 
the  continuous  parallel  arterial 
street  system  in  the  south  area 
adjacent  to  the  Southeast  Expressway. 
It  forms  a  continuous  link  with 
Morrissey  Boulevard,  Old  Colony 
Boulevard,  Columbia  Road  and  other 
arterials.   It  intersects  the 
Artery  corridor  just  south  of  the 
Dewey  Square  Tunnel.   At  this 
point,  Broadway  diminishes  in 
capacity  and  system  connections, 


causing  traffic  to  divert  onto  the 
Artery  in  order  to  connect  with  other 
principal  arterials  in  the  Downtown  area. 
Traffic  avoiding  the  Southeast  Expressway 
using  the  series  of  parallel  arterials 
must  eventually  cross  the  Broadway  Bridge 
and  either  enter  the  Artery  flow,  or 
find  alternative  Downtown  streets  for 
connections. 

II. C    SOUTH  AREA  TRAFFIC  CHARACTERISTICS 
II.C.l     Design  Deficiencies 

A  number  of  design  deficiences  have  been 
Identified  in  the  present  South  Section 
of  the  Central  Artery,  all  of  which  tend 
to  dimmish  service  capacity,  operating 
levels,  and  safety.   The  design  areas 
that  have  caused  problems  may  be  cateq- 
orized  as  follows: 

*Shoulders 

*Ramps  -  acceleration  and  decelera- 
tion lanes 
*Curves  and  grades 
*Sight  distances 
"^Connections  to  surface  streets 

In  the  remainder  of  this  section,  these 
aspects  of  highway  design  are  taken  up 
in  terms  of  design  standards,  and 
also  as  general  problems  of  the  Central 
Artery  South  Section  design. 

ir.C.l.a    Shoulders 

Under  ideal  construction  conditions,  it 
IS  usually  regarded  as  desirable  that 
modern  expressways  have  continous  paved 
shoulders  on  both  sides  of  the  paved 
Lanes.  As  rights-of-way  become  more  con- 
stricted, particularly  in  the  denser 
urban  areas,  this  standard  is  progressively 
modified.   The  first  fall-back  position 
is  to  have  intermittent  shoulders.   The 
second  is  to  have  no  shoulders. 


35 


As  indicated  above,  in  the  case  of  the 
South  Section  of  the  Central  Artery,  none 
of  these  standards  is  achieved.   Both  in 
the  Dewey  Square  Tunnel  and  on  the  viaduct 
sections  there  are  no  shoulders ,  no  break- 
down lanes,  and  no  breakdown  bays.   The 
Massachusetts  Turnpike  interchange  area  is  the 
only  place  in  the  Central  Artery  South 
Section  where  any  provision  is  made  for 
instances  of  vehicles  leaving  the  main 
travel  lanes  for  breakdown  or  other  rea- 
sons.  In  that  section  of  roadway,  there 
are  several  very  limited  sections  of  pave- 
ment off  the  main  travel  lanes. 

The  result  of  this,  as  indicated  above, 
is  that  even  the  most  minor  breakdowns  cut 
one-way  Central  Artery  capacity  by  one- 
third.   Accidents  are  more  frequent  than 
they  would  be  otherwise,  and  when  they  do 
take  place^  there  is  no  ready  opportunity 
either  for  taking  disabled  vehicles  to 
the  side  of  the  road  or  for  traffic  to  de- 
tour around-   Altogether,  the  lack  of 
breakdown  facilities  and/or  shoulders  is 
a  severe  design  deficiency  for  the  Central 
Artery  South  Section. 

Il.C.l.b   Ramps  -  Acceleration  and  Deceleration  Lanes 

The  original  plan  for  the  Central  Artery  South 
Section  relied  on  numerous  connections  with 
downtown  arterial  streets  to  provide  maxi- 
mum distribution  and  collection  services . 
This  caused  a  problem  in  terms  of  modern 
expressway  design,  partly  because  it  created 
many  entry  and  exit  points  to  and  from  the 
Artery  with  short  intervals  between  them, 
and  also  because  it  made  it  impossible  for 
adequate  acceleration  and  deceleration  lanes 
to  be  provided.   Only  in  a  few  cases  were 
any  acceleration  and  deceleration  lanes  pro- 
vided at  all,  and  typically  these  are  of 
inadequate  length. 

In  modem  expressway  design,  interchanges 
should  be  as  infrequent  as  possible  -  pre- 
ferably a  mile  or  more  apart,  and,  where  the 
design  speed  is  50  MPH,  acceleration  and  de- 
celeration lanes  should  respectively  be  a 
minimijm  of  1,000  feet  and  450  feet  long. 
The  distance  between  an  entry  and  a  sub- 
sequent exit  should  be  no  less  that  650  feet. 
Also,  it  is  generally  desired  that  ramps 
enter  and  exit  from  and  to  the  right. 


•?« 


In  the  case  of  the  Central  Artery  it 
would  not  be  possible  under  any  circuin- 
stances  to  meet  the  standard  for  distance 
between  interchanges  and  still  allow  nec- 
essary expressway  connections  and  collection- 
distribution  functions.   Further,  it  would 
be  diffi-cult  to  fully  meet  the  acceleration, 
deceleration,  and  ramp  spacing  standards. 
Nonetheless,  the  standards  have  been  breached 
more  in  the  Central  Artery  South  Section 
than  necessary  and  desirable  under  today's 
conditions . 

Ramp  spacing  is  shown  in  Figure  3     fox    south- 
bound and  northbound  roadways  of  the 
South  Section.  As  shown,  there  are  a  total 
of  ten  ramps  southbound,  and  nine  ramps 
northbound  in  the  less  than  two  miles  of 
the  section.   Ramp  spacing  varies  between 
450  ft.  and  1,450  feet  southbound,  and  be- 
tween 500  and  2,800  feet  northbound.   In 
three  cases  it  would  be  physically  impossible 
to  meet  the  on-off  standard  because  of  ramp 
spacing.   In  two  cases  ramps  exit  to 
and  enter  from  the  left.  A.s  indicated  above, 
acceleration  and  deceleration  lanes  are 
rarely  provided  at  all.   In  fact,  if  all 
the  existing  ramps  were  to  have  accelera- 
tion and  deceleration  lanes  of  standard 
length,  such  lanes  would  occupy  approx- 
imately one-third  of  the  length  of  the 
Central  Artery  South  Section.   As  such, 
a  substantial  portion  of  the  Artery's  length 
would  have  an  extra  lane  in  each  direction 
only  for  the  purpose  of  acceleration  and  de- 
celeration.  As  the  facility  presently  op- 
erates, the  right-hand  travel  lane  largely 
performs  this  function,  leaving  an  effec- 
tive total  of  two  travel  lanes  in  each  dir- 
ection. 

To  avoid  the  worst  ramp  problems,  in  two 
instances  where  an  exit  follows  an  entrance 
with  too  little  space  in  between,  one  of 
the  ramps  has  been  closed  either  at  peak 
hours  or  permanently.^  The  northbound 
Broadway  on-ramp  is  closed  at  peak  hours , 
and  the  northbound  Lincoln  Street  off-ramp 

^The  explicit  reason  for  closure  was  not  in- 
adequate space  between  ramps.   In  the  case_ 
of  the  Broadway  entry  the  ramp  was  closed  in 
the  AM  peak  because  Central  Artery  traffic 
was  attempting  to  avoid  the  Dewey  Square  (cont'd) 


37 


in  the  Dewey  Square  Tunnel  is  closed  per- 
manently.   Even  with  these  changes,  how- 
ever, lack  of  acceleration  and  decelera- 
tion lanes  makes  access  to  and  egress  from 
the  Central  South  Section  a  difficult  and 
dangerous  proposition. 


1 1 .  C . 1 . c    Curves  and  Grades 


Design  criteria  for  curves  and  grades  on 
an  urban  expressway  with  a  design  speed  of  5  0 
MPH  call  for  a  minimum  radius  of  curvature 
of  830  feet,  and  a  maximum  grade  of  4  % ,  In  the 
Central  Artery  South  Section,  these  stand- 
ards are  generally  observed,  but  they  are 
breached  in  certain  instances  in  the  Dewey 
Square  Tunnel.   There,  a  compound  reverse 
curve  has  a  minimum  radius  of  700  feet,  and 
a  corresponding  design  speed  of  40  MPH. 
This  is  a  more  serious  problem  in  the  con- 
fines of  a  tunnel  than  it  would  be  in  the 
open,  because  there  is  less  room  for  error. 
The  tunnel  also  has  minor  grade  problems. 
At  both  tunnel  portals,  there  are  grades  of 
approximately  5%. 


Il.C.l.d   Sight  Distances 


Sight  distances  can  become  a  problem  either 
for  horizontal  or  vertical  curves.   In  the 
case  of  a  horizontal  curve,  the  problem  is 
seeing  an  obstacle  around  the  corner,  and 
having  adequate  time  to  stop.   In  vertical 
curves,  the  problem  relates  to  being  able 
to  see  over  the  crest  of  a  hill,  or  occ- 
asionally, under  the  roof   of  a  tunnel 
where  it  switches  from  going  down  to  going 
up.   In  the  case  of  50  MPH  facility,  a 
sight  distance  of  350  feet  for  horizontal 
and  vertical  curves  is  considered  adequate. 

As  applied  to  the  Central  Artery  South 
Section,  sight  distance  is  a  problem  in 
one  place:   the  4  0  MPH  section  of  the 
Dewey  Square  tunnel.   In  that  section, 
sight  distances  are  restricted  to  275 

(continued) 

Tunnel  queue  by  exiting  the  expressway  at 
Southhampton  Street,  traveling  along  the 
Frontage  Road,  and  then  re-entering  the  ex- 
pressway at  Broadway.  In  the  case  of  Lincoln 
Street,  ramp  traffic  was  backing  up  into  the 
Dewey  Square  tunnel  and  producing  Central 
Artery  blockages. 


38 


4h 

% 

i^ 

m 

\* 

It 

1^ 

1  ^ 

w 

1500' 


1400' 


1400' 


1400' 


900' 


1400' 


800' 


450 


SOUTHBOUND    LANES 


1600' 


1200' 


2800' 


900' 


1000< 


1850' 


750' 


NORTHBOUND    LANES 

»• 


RAMP    SPACING  DIAGRAM 
CENTRAL  ARTERY 
SOUTH   AREA  ^^""^^  ^ 


II. 


II. 


feet  for  the  inner  lane  of  the  southbound 
roac.way  and  the  outer  lane  of  the  north- 
bound roadway.   In  neither  direction  is 
the  problem  of  concern  during  peak  periods 
when  traffic  moves  slowly.   At  off-peak 
periods,  however,  traffic  speeds  in  the 
tunnel  approach  45-50  MPH  and  sight  distances 
do  cause  problems  when  traffic  suddenly 
backs  up  because  of  a  breakdown  or  for 
other  reasons. 

Il.C.l.e   Connections  to  Surface  Streets 

In  ideal  urban  expressway  design,  access 
and  egress  are  promoted  by  the  use  of  par- 
allel one-way  frontage  roads  on  either  side 
of  the  main  expressway  facility.   For  entry 
to  the  expressway,  the  frontage  roads  provide 
relatively  unimpeded  access  to  the  ramps. 
For  egress,  the  frontage  roads  provide 
capacity  behind  intersections  and  traffic 
signals  so  that  traffic  exiting  the  express- 
way is  less  likely  to  back  up  into  the  ex- 
pressway itself.   Also,  in  times  of  emer- 
gency or  expressway  repairs,  frontage  roads 
can  act  as  reasonably  efficient  detours. 

North  of  Dewey  Square,  Atlantic  Avenue  and 
Purchase  Street  form  parallel  frontage  roads 
with  ramps  directly  to  and  from  the  tunnel. 
These  two  streets  connect  with  the  rest  of 
the  downtown  street  network,  but  are  some- 
what limited  in  their  usefulness  as  front- 
age roads  because  they  are  adjacent  to  the 
Central  Artery  for  only  a  four  block  stretch. 

South  of  Dewey  Square,  a  roadway  on  top  of 
the  tunnel  acts  in  part  as  a  frontage  road. 
This  function  is  also  limited,  however,  be- 
cause in  this  area  the  Artery  is  on  an  align- 
ment which  cuts  diagonally  across  the  grid 
pattern  of  surface  streets.   In  this  area, 
various  plans  for  surface  street  changes  have 
been  proposed  over  the  years  to  improve 
access  between  the  tunnels  and  surface  streets, 
and  to  better  serve  development.   Yet,  an 
effective  overall  plan  appears  to  depend  pri- 
marily on  changes  in  the  Artery  itself. 

South  of  the  Dewey  Square  Tunnel,  the  Artery 
design  is  at  least  in  part  standard  with  r.^- 
gard  to  frontage  roads.   Southbound,  Albany 


street  acts  as  a  frontage  road  from  the  tunnel 
portal  area  to  the  Massachusetts  Avenue  inter- 
change.  Northbound,  a  frontage  road  exists 
from  Southampton  Street  south  of  the 
Central  Artery,  to  the  Massachusetts  Turnpike 
interchange. 

II. C. 2     Traffic  Characteristics 

A  complete  study  of  present  traffic  charac- 
teristics in  the  South  Area  would  include 
information  on  traffic  origins  and  destina- 
tions, volumes,  service  levels,  and  accidents 
both  for  expressway  and  local  street  travel. 
At  the  present  time,  South  Area  corridor  level 
origin-destination  data  are  unavailable,  and 
information  on  traffic  volumes,  service  levels, 
and  accidents  has  been  compiled  only  for  the 
Central  Artery  in  the  South  Area.   Thus,  in 
this  section,  detailed  traffic  analysis  is 
restricted  to  consideration  of  the  South  Sec- 
tion of  the  Central  Artery.   Traffic  charac- 
teristics for  local  South  Area  streets  are 
treated  only  as  broad  general  flows.   In  most 
of  the  analysis,  data  are  from  regular  counts 
of  the  DPW,   In  certain  cases,  DPW  data  have 
been  modified  by  new  information  collected  in 
1977  as  part  of  the  Southeast  Expressway 
Downtown  Express  Lane  Project. 

II.C.2.a   Volumes 

As  indicated  above,  the  basic  traffic  problem 
in  the  South  Area  is  insufficient  expressway 
and  local  street  capacity  to  handle  existing 
amounts  of  traffic  at  reasonable  levels  of 
service.   This  is  seen  in  terms  of  substantial 
peak  period  queuing  on  the  Central  Artery 
south  of  the  Dewey  Square  Tunnel ,  and  in 
terms  of  extreme  peak  period  congestion  of 
local  and  arterial  streets  leading  into  down- 
town Boston  from  the  Boston  South  End  and 
from  South  Boston.   The  problem  of  downtown- 
destined  and  through  traffic  avoiding  the 
Dewey  Square  bottleneck  by  traveling  on  neigh- 
borhood streets  is  disruptive  to  local  neigh- 
borhoods .  During  peak  periods,  a  considerable 
amount  of  downtown-destined  traffic  exits  west 
from  the  Central  Artery  at  the  Massachusetts 
Avenue  interchange,  and  then  goes  generally 
north  toward  the  central  area  of  Boston  via 
Albany  Street,  Washington  Street,  Tremont 


42 


Figure  ]_o 

Average  Daily  Traffic  (ADT)  in  South  Area 
Entering,  Exiting  and  On  the  Artery 


SOUTHBOUSD 


Location 


Entering 


South  of  High  Street 

Purchase  Street  Entrance    13,350 


Summer  Street  Exit 
Congress  Street  Ent. 
Beach  Street  Exit 


5,350 


Albany  St/Turnpike  Exit 

Kneeland  St/Turnpike  Ent.   16,000 


Albany  St.  Exit 

Albany  St.  Ent. 

Mass .  Avenue  Exit 

Mass.  Avenue  Ent. 
South  of  Mass.  Avenue 

NORTHBOUND 


13,100 


3,050 


Exiting 


8,900 

3,400 
15,150 

4,100 

8,900 


On  Artery 
57,100 
70,450 
61,550 
66,900 
63,500 
48,350 
64,350 
60,250 
73,350 
64,450 
67,500 


Locat  ion 

South  of  Mass.  Ave. 
Mass .  Avenue  Exit 

Mass.  Avenue  Ent. 

E.  Berkeley  St.  Ent. 

Kneeland  St/Turnpike  Exit 

Turnpike/Broadway  Ent. 

South  Station  Ent, 

Northern  Ave.  Exit 
North  of  Northern  Ave. 


Entering 

Exiting 

On  Artery 

~  ^ 

_ 

56,100 

- 

7,100 

49,000 

5,850 

— 

54,850 

8,450 

- 

63,300 

— 

16,900 

46,400 

16,700 

— 

63,100 

8,900 

— 

72,000 

— 

16,000 

56,000 

Source:   1972  counts  by  the  Mass.  Dept  of  Public  Works 


street,  or  Columbus  Avenue.   This  traffic 
avoiding  the  Central  Artery  substantially 
worsens  peak  period  traffic  conditions 
throughout  the  South  End  of  Boston. 

Similarly,  other  traffic  exits  from  the 
expressway  north  or  south  of  Southampton 
Street  to  travel  to  or  through  the  Boston 
Central  Area  via  South  Boston,  thus  sub- 
stantially adding  to  local  traffic  in  that 
area.   In  the  South  Boston  case,  the  pri- 
mary arterial  streets  used  are  L 
Street,  Dorchester  Avenue,  and  the  express- 
way frontage  road.  L  Street  may  be 
used  to  go  to  Summer  Street,  Congress  Street, 
or  Northern  Avenue,  all  of  which  cross  Fort 
Point  Channel  into  downtown  Boston  north  of 
South  Station.   From  Dorchester  Avenue, 
Broadway  and  Berkel^  Street  may  also  be  used 
to  get  to  downtown.   These  latter  streets 
are  similarly  the  normal  routes  to  downtown 
Boston  from  the  frontage  road. 

A  further  problem  is  caused  by  the  fact  that 
a  number  of  these  local  and  arterial  streets 
come  together  in  the  South  Area  near  the 
Massachusetts  Turnpike  interchange.   Broad- 
way and  Berkeley  Street  both  intersect  the 
streets  coming  up  from  Massachusetts  Avenue, 
and  Broadway,  itself,  has  a  smaller  capacity 
north  of  the  Turnpike  interchange  than  it 
does  south  of  it.   Similarly,  Albany  Street 
is  one-way  southbound  in  the  vicinity  of 
the  interchange.   For  these  reasons,  not 
only  does  the  expressway  system  have  a  bottle- 
neck in  the  South  Area,  but  the  local  and 
arterial  streets  do  as  well. 

The  relationship  between  local  and  express- 
way traffic  may  not  be  seen  directly,  but  may 
be  inferred.,  from  the  expressway  traffic 
volumes  shown  in  Figures  11  and  12  for  the 
A.M.  and  P.M.  peaks.   In  Figure  11,  for 
the  A.M.  peak,  it  is  seen  that  northbound 
expressway  traffic  diminishes  from  6,900 
vehicles  per  hour  south  of  Southampton  Street 
to  4,800  vehicles  per  hour  in  the  Dewey  Square 
Tunnel.   Including  the  additional  1, 100 
vehicles  per  hour  from  the  Turnpike  this 
amounts  to  a  total  diminishment  of  3,2  00 
vehicles  per  hour  or  40%  of  a  total  of 
8000.   Although  a  significant  portion 
of  the  net  3,200  vehicles  per  hour 
exiting  the  expressway  between  Southampton 


44 


6900 


6500     5000 


4200 


4700 


SOUTHBOUND  LANES 


NORTHBOUND    LANES 


1976   A.M.  PEAK  ^^^'^'^  i^ 

VEHICLES  PER  HOUR- 
CENTRAL   ARTERY 
SOUTH  AREA 


NORTHBOUND   LANES 


1976  R  M.  PEAK         Figure  12 
VEHICLES  PER  HOUR: 
CENTRAL  ARTERY 
SOUTH  AREA 


street  and  the  tunnel  probably  have  destin- 
ations within  the  South  End  and  South  Bos- 
ton, it  seems  likely  that  much  of 
this  traffic  is  either  downtown-destined  or 
through  traffic.   This  may  be  seen  by  the 
fact  that  only  1,900  vehicles  per  hour  leave 
the  expressway  southbound  between  the  tunnel 
and  Southampton  Street  during  the  A.M.  peak. 
If  there  were  no  substantial  downtown-des- 
tined and  through  component  to  northbound 
traffic  on  local  streets  in  the  South  Area, 
north  and  southbound  exiting  expressway 
volumes  would  presumably  be  roughly  equal. 

Two  other  relevant  expressway  traffic  charac- 
teristics may  be  seen  in  Figure  11.   The 
first  is  that  the  actual  minimum  volume  north- 
bound on  the  Central  Artery  South  Section  is 
not  in  the  tunnel,  but  rather  between  the 
Kneeland  Street  exit  south  of  the  tunnel,  and 
the  Turnpike  entry,  also  south  of  the  tunnel. 
This  does  not  demonstrate  a  particular  con- 
striction at  this  point  on  the  Central  Artery. 
Rather,  it  shows  the  effects  of  traffic 
leaving  the  tunnel  queue,  prior  to  entry  of 
the  Turnpike  traffic.   The  second  traffic 
characteristic  seen  is  that  volumes  on  the 
southbound  lanes  of  the  Artery  during  the 
A.M.  peak  show  much  less  variation  than  those 
on  the  northbound  lanes .   They  vary  only 
between  3,200  and  4,900  vehicles  per  hour. 
The  difference  between  northbound  and  south- 
bound roadways  reflects  the  absence  of  traffic 
with  a  downtown-destined  component  in  the 
southbound  lanes . 

As  shown  in  Figure  12  ,  the  P.M.  peak  is 
essentially  the  reverse  of  the  A.M.  peak. 
Southbound,  peak  hour  traffic  builds  up  from 
5,000  vehicles  per  hour  passing  through  the 
Dewey  Square  Tunnel,  to  a  total  of 
6  200  at  Southampton  Street.    Northbound, 
there  is  evidence  of  P.M.  queuing, 
with  6,700  vehicles,  5,300  from 
south  of  Southampton  Street,  and  400   from 
the  Turnpike,  diminishing  to  only  3,8  00  ve- 
hicles going  through  the  tunnel.   From  this 
it  is  evident  that  local  streets  in  the  South 
End  and  South  Boston  are  being  used  as  de- 
tours around  the  Dewey  Square  Tunnel  both  in 
the  A.M.  and  P.M.  peaks. 


49 


II.C.2.b   Service  Levels 


For  purposes  of  analysis  and  comparison,  a 
number  of  levels  of  service  have  been  defined 
by  the  Highway  Research  Board  to  describe 
the  operations  of  highways  vmder  a  variety 
of  traffic  conditions.   These  levels  of 
service,  as  defined  for  expressways,  range 
from  "A"  with  free  flow,  no  congestion  and 
speeds  in  excess  of  60  MPH,  to  "F"   where 
demand  cannot  be  satisfied,  and  traffic  is 
"stop-and-go. "   Figure  13  gives  descriptions 
of  traffic  flow,  typical  speeds,  and  what  is 
known  as  the  Volxame/Capacity  Ratio  for  levels 
of  service  "A"   through  "F"  as  applied  to  ex- 
pressway facilities.   Ideally,  it  is  desired 
that  highways  be  designed  so  that  they  can 
operate  at  a  "C"  level  of  service  for  the 
thirtieth  heaviest  hoxir  of  the  year.   Also, 
capacity  is  defined  as  the  amount  of  traffic 
that  a  highway  can  handle  in  an  hour  at  level 
of  service  "E"/   The  design  volume  is  the 
traffic  estimated  to  use  a  facility  daily 
during  the  design  year  -  usually  20  years 
from  the  completion  of  construction. 

The  Central  Artery  South  Section,  as  a  six  . 
lane  facility,  has  a  basic  hourly  capacity 
of  5530  vehicles  per  hour  in  each  direction. 
Its  corresponding  design  volume  is  77,000 
vehicles  per  day.  (  At  present  it  is  carrying 
135,000  vehicles  per  day.)   Because  of  the 
design  problems  of  the  Dewey  Square  Tunnel 
area,  however,  the  actual  capacity  for  level 
"E"  service,  is  less  that  5530  vehicles  hourly. 
The  excessive  grades  at  the  tunnel  portals 
alone  have  the  effect  of  reducing  "E"  level 
capacity  to  4,260  vehicles  per  hour  in  each 
direction.   Similarly,  the  closely  spaced 
ramps,  lack  of  acceleration -and  deceleration 
lanes,  excessive  curves,  and  lack  of  break- 
down facilities  or  shoulders  reduce  capacity 
even  more.   It  is  therefore  not  surprising 
that  the  Dewey  Sgure  tunnel  area  operates 
at  level  "F"  for  a  number  of  hours  each  day, 
and  that  substantial  queues  develop  south  of 
the  tunnel  during  peak  periods.   At  the  pre- 
sent time,  operating  speeds  for  queue  peak 
hours  range  between  0  and  27  MPH,  and  aver- 
age 12  MPH. 2 


2  Southeast  Expressway  Downtown  Express  Lane 
Project,  April,  1977. 


sn 


The  fact  that  both  directions  of  the  Dewey 
Square  tunnel  handle  volumes  of  near  to  or 
about  5,000  vehicles  per  hour  under  forced 
flow  conditions  during  peak  hours,  indicates 
that  the  absolute  capacity  of  the  Dewey 
Square  Tunnel,  as  presently  constituted,  is 
about  5,000  vehicles  per  hour  in  each  dir- 
ection.  This  is  obviously  substantially 
less  than  the  volume  of  traffic  that  would 
use  the  tunnel  instead  of  detouring  through 
local  streets,  if  the  tunnel  had  more 
capacity. 

Figure  13 
EXPRESSWAY  SERVICE  LEVELS 

Level  of  Service      Description      Speed      Volume/Capacity  Ratio 

A  Free  Flow  >  60  .35 
B  No  Congestion  55-60  .50 
C  Light  Congestion  50-55  .57 
D  Moderate  Congestion  40-50  .68 
E  Heavy  Congestion  30-35  1.00 
P  Demand  Cannot  Stop  >1.00 
be  Satisfied       and  Go 


Source:   Highway  Capacity  Manual,  1965,  Highway  Research  Board 
II.C.2.C   Accidents 


Fully  access  controlled  freeways  are  the 
safest  highway  facilities  we  can  build. 
Based  on  national  statistics,  they  are 
nearly  twice  as  safe  as  the  average  of  other 
facilities,  having  a  fatality  rate  of  about 
two  and  one-half  deaths  per  one  hundred 
million  miles  of  vehicle  travel,  as  compared 
with  the  national  average  of  four  deaths  per 
htindred  million  miles  of  other  facilities. 3 
Urban  expressways  are  even  safer  than  rural 
ones,  primarily  because  they  handle  extremely 
heavy  travel  volumes.   The  national  fatality 
rate  in  1971  for  fully  access  controlled 
urban  expressways  was  1.0  0  deaths  per  one 
hundred  million  miles..^   Accident  and  injury 


3  In  house  study  of  accident  data  by  E.N. 
Kashuba  for  the  Highway  User  Investment 
Study,  1971,  F.H.W.A. 

4  Fatal  and  Injury  Accident  Rates  on  Federal 
Rates  on  Federal  Aid  and  Other  Highways 
Svstems,  1975,  F.H.W.A. 


statistics  are  similar.  Both  in  accidents 
and  injuries,  access  controlled  expressway 
facilities  are  much  safer  than  other  high- 
ways . 

As  measured  by  these  indices,  the  Central 
Artery  South  Section  is  not  a  safe  facility. 
During  1975,  it  experienced  a  total  of  449 
reported  accidents,  involving  190  injuries 
and  three  fatalities .   As  shown  in  Figure 
14,  the  accident  rate  of  505  accidents  per 
one  hundred  million  vehicle  miles  was  more 
than  twice  the  national  average  for  urban 
expressways  carrying  in  excess  of  76,000 
vehicles  per  day.   The  injury  rate,  at  214 
per  one  hundred  million  vehicle  miles  was 
almost  twice  the  national  rate  of  134.   And 
the  fatality  rate  of  3.38  in  1975  was  over 
three  times  the  national  average.   Because 
the  1975  rate  is  based  on  only  three  fatal- 
ities, it  might  appear  to  be  a  questionable 
statistic  because  of  small  sample  size.   But 
over  a  longer  time  period,  fatalities  still 
average  over  twice  the  national  rate,  with  a 
total  of  eight  fatalities  having  been  ex- 
perienced in  traffic  accidents  on  the  South 
Section  of  the  Central  Artery  during  the 
years  1973-1976. 


Figure  14:   Comparative  Accident  Rates 
add  Fatality  Rates  for  Fully  Access 
Controlled  Expressway  Facilities: 
Central  Artery  South  Section  and 
National  Statistics 


U.S.  Urban  Expy ' s 
with  Six  or  More 
Lanes  and  >  76,000 
A.D.T.  (1971)5 


239 
134 

1.00 


Per  one  hundred  million  vehicle  miles  of 
travel.   National  statistics  from  in-house 
study  of  accident  data  by  E.N.  Kashuba  for 
the  Highway  User  Investment  Study,  1971, 
Federal  Highway  Administration. 


Central  Artery 

South  Section 

(1975) 

Accidents 

505 

Injuries 

214 

Fatalities     3.38 

52 


Atlantic  Ave. 


From  the  Mass 
Front  ag 


To  Kneelond  St  & 
Pike 


•• \*        H 


9       I*       If 


XT 


From  Broadway 


fx-'i/"''/'' 


^ 


+* 


»«'-'*'''—/f  • 


■«  vt* 


♦t-*j//'/^/* 


A 


or-ex/i.0*^/^  ~ 

r — h* M 

-• H 

,.^-»t// »••/'• 
ei-u/i'^/'' 

/J- »'/»«»»/.• 
,3.,7/iiot/e 
«-«/«»—//' 


,^lT>^»yi-- 


■e  -  rf/'**^^ 

— — k 


LEGEND 


.^       L' 

Rear  End 

<.      Ik 

<    '■^ 

Angle 

Lost  Control  or  Ran  Off  Road  a/or  Hit  Fixed  Object 

N<^ 

• 

Injury 

* 

Fatality 

r^ 

Parked  or  Stalled  Vehicle 

0 

Pedestrian 

@ 

No.  of  Vetiicles   (if  more  ttian  3) 

03/11 

Marcti  II,  1975 

1700  (hrs.) 

5  00  p.m. 

P 

Property  Damage 

I 

Injury 

lati/xxtf/X'  ■ 
,«'.<t/"»y'* 

a/.i^/xf/r- 


■> 


07'arT/fVf^' 


From  Mass 


To  Mass  Ave. 


NOTE^     Of  the  449  identified  accidents 
in  the  South  Section  of  the  Central 
Artery,  382  hove  been  plotted  (210 
Northbound,  172  Southbound).    There  is 
insufficient  data  to  plot  the  remaining  67 
accidents  (i.e.  Dote,  Specific  Location, 
Type  of  Accident,  Etc ) 


1 


COLLISION  DIAGRAM 
NORTHBOUND 
CENTRAL  ARTERY 
SOUTH  AREA 


Figure    15A 


vjo  Atlantic  Ave 


From  the 
Mass.  PikeA 
Frontage  Rd/f  O 


From  Broadway 


legend: 


I  -   5  Accidents 


6-10  Accidents 


11-15  Accidents 


16-20  Accidents 


000 


TRAFFIC    DIRECTION 


ACCIDENTS  BY  LOCATION.  CENTRAL  ARTERY  SOUTH  SECTION, 1975-NORTHBOUND 


0    0   0 


NOTE: 

Of  the  449  identified  accidents  in  the 
South  Section  of  the  Central  Artery, 
382  (about  85;<)  have  been  plotted. 
There  is  insufficient  data  to  plot  the 
remaining  67. 


ACCIDENTS  BY  LOCATION 
CENTRAL  ARTERY 
SOUTH  AREA 


Figure    15 


^ 


clo'/'i'V'' 
yx-n//»tY^  - 


— H     H     - 


— H ^ 

0  9  iv//*^^/^- 


-H ^ 


nr-l*/""/^- 
ai-o-r/eff'//' 

(T)  p^-u/^m/x- 


— -s 


Of»t/  0700/y<» 
o9-ay//ioo/:r:- 


^Ttf'-i^T^J*^^* 


„.,r/,t,f//' 


o^/*ixyir«- 


■^»  70&y^ 
Albany  St. 


From  Albany  St 


-Ht 


aT-o9/fTm»/^ 

o7-0d//4.P^/' 


o9-0r/»rcc/^ 


IN., 


\ 


From  the  Mass 
Pike 


LEGEND 


^         L^ 

Rear  End 

<«         1^ 

<      *^ 

Angle 

Lost  Control  or  Ran  Off  Road  a/or  Hit  Fixed  Object 

N<^ 

• 

Injury 

* 

Fatality 

f^^ 

Parked  or  Stalled  Vetiicle 

0 

Pedestrian 

® 

No.  of  Vehicles  (if  more  ttian  3) 

03/11 

Marcti  II,  1975 

1700  (hrs.) 

500  p.m. 

P 

Property  Damage 

I 

Injury 

NOTE^     Of  the  449  identified  accidents 
in  the  South  Section  of  the  Central 
Artery,  382  have  been  plotted  (210 
Northtwund,  172  Southbound).    There  is 
insufficient  data  to  plot  the  remaining  67 
accidents  (ie.  Date,  Specific  Location, 
Type  of  Accident,  Etc ) 


COLLISION  DIAGRAM: 

SOUTHBOUND  Figure    16^ 

CENTRAL  ARTERY 
SOUTH  AREA 


i[ 


••—  Dewey  Square  Tunnel- 


0 


00 


LEGEND: 


1-5  Accidents 


6-10  Accidents 


11-15  Accidents 


16-20  Accidents 


20-25  Accidents 


7 


10 


From 
Kneeland  St. 


ACCIDENTS  BY  LOCATION:  CENTRAL  ARTERY  SOUTH  SECTION,  1975 -SOUTHBOUND 


0        ® 


TRAFFIC    DIRECTION 


ACCIDENTS  BY  LOCATION 
CENTRAL  ARTERY 

SOUTH     AREA  Fxgure    16 


Albany  St. 


0 


From 
'Mass.  Ave. 


note: 

Of  the  449  identified  accidents  In  the 
South  Section  of  the  Central  Artery, 
382  (about  85^-)  have  been  plotted. 
There  is  insufficient  data  to  plot  the 
remaining  67. 


Accidents  by  location  are  shown  for  the  Sc.— .h 
Section  of  the  Central  Artery  in  Figures  15 
and  16  which  are  respectively,  for  north- 
bound and  southbound  Artery  roadways.   As 
can  be  seen  in  Figure  15,  northbound  there  are 
two  areas  on  the  roadway  where  there  are  more  • 
accidents  than  elsewhere.   One  is  just  be- 
fore and  just  after  entry  to  the  Dewey  Square 
Tunnel.   Most  of  these  accidents  are  related 
to  merges  from  the  Massachusetts  Turnpike, 
and  driver  uncertainties  entering  the  tunnel. 
The  other  heavy  accident  area  is  the  Artery 
section  between  the  Massachusetts  Avenue 
interchange,  and  the  Kneeland  Street  and 
Massachusetts  Turnpike  exit.  Here  the  problems 
have  primarily  to  do  with  weaving  movements 
from  the  Massachusetts  Avenue  entry,  to  the 
Kneeland  and  Turnpike  exit.  They  also  have 
to  do  with  with  merges  from  the  Broadway 
entry  ramp,  and  with  the  tunnel  queue.   There 
are  substantial  numbers  of  accidents  through- 
out the  length  of  the  northbound  roadway  of 
the  Artery's  South  Section.   This  is  because 
of  the  general  problem  of  heavy  Artery  traffic 
volume,  long  queues,  the  many  ramps,  the  lack 
of  adequate  acceleration  and  deceleration 
lanes,  and  the  lack  of  shoulders  01^  breakdown 
lanes  or  bays. 

As  seen  in  Figvire  16  /  the  situation  south- 
bound is  similar  to  that  northbound.   The 
highest  numbers  of  accidents  happen  in  the 
Dewey  Square  Tunnel  and  near  the  Massachu- 
setts Avenue  interchange.   Tunnel  problems 
probably  relate  mostly  to  design  standards 
of  the  tunnel,  and  to  weaving  movements  be- 
ing made  prior  to  leaving  the  Artery  at  the 
Turnpike.   At  the  Massachusetts  Avenue 
interchange  area,  the  problem  is  most  likely 
due  in  major  part  to  the  conflicts  between 
traffic  entering  .from  Albany  Street,  and 
traffic  desiring  to  leave  at  the  Massachusetts 
Avenue  interchange. 

Figure  17  shown  accidents  by  type  for  the  South 
Section  of  the  Central  Artery.   As  can  be 
seen,  both  northbound  and  southbound,  rear- 
end  and  angle  accidents  occur  in  almost  equal 
numbers,  and  amount  to  about  85%  of  the  total. 
This  is  a  direct  result  of  the  two  outstand- 
ing problems  of  the  Central  Artery  South 
Section:  inadequate  capacity  and  insufficient 
merging  opportunities.   The  rear-end  accid- 
ents are  in  large  measure  the  result  of 


heavy  stop-and-go  queued  traffic.   The  angle 
accidents  are  the  results  of  overly  frequent 
ramps,  and  lack  of  acceleration  and  decelera- 
tion lanes. 

Even  the  remaining  15%  of  the  accidents  can  in 
considerable  measure  be  attributed  to  overly 
heavy  traffic  and  inadequate  merging  oppor- 
tunities.  In  most  of  these  cases  the  accident 
consisted  of  a  single  vehicle  running  off  the 
road  and  into  the  cement  or  metal  roadside 
barrier.   In  many  cases  this  was  because  the 
driver  was  unable  to  merge  into  traffic,  or 
was  driven  into  the  side  of  the  road  by 
another  automobile  preparing  to  exit. 

Figure  17 

ACCIDENTS  BY  TYPE:  CENTRAL  ARTERY  SOUTH 
SECTION,  1975 


Accident  Type     Northbound     Southbound 

Number   Per  Cent   Number   Per  Cent 


Rear  End 

92 

44% 

72 

42% 

Angle 

87 

41% 

70 

41% 

Other  . 

31 

15% 

30 

■  17% 

Total 210 Tool 172 100% 

Totals  here  represent  only  about  85%  of 
actual  reported  accidents.  Insufficient 
data  were  included  in  reports  for  the 
ether  15%  to  allow  dividing  into  categories, 


Several  further  comments  are  relevant  as  re- 
gards accidents.   First,  it  is  worthwhile 
noting  that  68%  of  the  accidents  on  the 
Artery's  South  Section  involved  property 
damage  only,  and  84%  were  multiple  vehicle 
accidents.   This  is  again  a  result  of  heavy 
traffic,  peak  period  queueing  with  stop-and- 
go  traffic,  and  inadequate  opportunities  for 
merging  and  weaving. 

Second,  injury  producing  accidents  occurred 
in  much  higher  proportions  during  the  period 
from  9  PM  to  5  AM  than  during  the  day.   All 
but  one  of  the  fatal  accidents  occurred  dur- 
ing the  nighttime  hours,  and  injury  producing 
accidents  occurred  at  a  50%  higher  rate  dur- 
ing this  time.   With  substantially  reduced 


volumes  during  the  night  off-peak  period,  ve- 
hicle speeds  are  higher  thereby  increasing  the 
probability  of  injury  during  a  crash.   This 
alone,  however,  does  not  explain  the  high 
fatality  and  injury  rates  during  the  9  PM- 
5  AM  period.   The  prevailing  higher  speeds, 
together  with  the  sub-standard  design  features 
of  the  roadway  offer  a  more  satisfactory  ex- 
planation. 

Finally,  the  accidents  considered  here  rep- 
resent only  reported  accidents.   Experience 
throughout  the  U.S.  has  shown  that  only  20- 
40%  of  property  damage-only  accidents  are  nor- 
mally reported  to  public  authorities.   Many 
■  researchers  suggest  that  to  compensate  for 
this  under-reporting,  property  damage-only 
accidents  should  be  adjusted.   In  the  absence 
of  more  precise  information  on  the  degree 
of  under-reporting,  multiplying  the  reported 
accidents  by  a  factor  of  2.5  (assuming  a  40% 
reporting  level) ,  would  yield  a  total  of  904 
accidents  for  the  Artery's  South  Section, 
760  having  property  damage  only,  and  144 
involving  injury  or  fatality. 

II. D.      Environmental-  Conditions 

Highway  construction  in  the  South  Area  of  the 
Central  Artery  Corridor  can  be  expected  to 
have  environmental  impacts  related  to  air 
quality,  noise,  and  water  quality.  In  this 
section,  these  three  indices  of  environmental 
conditions  are  assessed  in  teirms  of  qualitative 
and  quantitative  measures,  and  then  general 
statements  are  made  regarding"  potential  im- 
pacts that  might  result  from  future  South  Area 
construction . 


II.D.l     Air  Quality 

The  Federal  Environmental  Protection  Agency 
has  established  ambient  air  quality  standards 
for  carbon  monoxide,  hydrocarbons,  and  oxides 
of  nitrogen,  all  of  which  are  pollutants  pro- 
duced through  the  use  of  automobiles.   Car- 
bon monoxide  and  hydrocarbons  tend  to  be 
formed  in  high  concentrations  by  slow  moving 
traffic.   Oxides  of  nitrogen  are  produced  in 
greater  quantities  by  traffic  moving  at  higher 
speeds . 


59 


In  the  South  Area,  the  most  important  source 
of  these  pollutants  is  traffic,  both  on  local 
streets  and  on  the  portion  of  the  Central 
Artery  that  traverses  the  area.   Traffic  vol- 
umes using  local  streets,  particularly  dur- 
ing off-peak  hours,  contribute  a  high  percen- 
tage of  existing  carbon  monoxide  and  hydro- 
carbons, because  this  traffic  travels  at  slow 
speeds  in  stop-and-go  conditions .   The  impact 
is  felt  directly  by  adjacent  businesses,  office 
buildings,  and  other  developed  areas.   The 
Artery  itself  is  located  in  tunnel  for 
about  2500  feet   or  about  30  percent  of  its 
length  through  the  South  Area.   The  section 
in  tunnel  is  ventilated  by  means  of  four 
stacks  located  in  the  vicinity  of  South 
Station;  these  act  as  point  sources  of  auto- 
motive pollutants  to  the  surrounding  areas . 

A  measurement  program  designed  to  monitor 
background  CO  levels  in  the  study  area  was 
undertaken  as  part  of  the  1975  South  Station 
Urban  Renewal  Project  Environmental  Impact 
Report. 6  Two  monitoring  stations  were  sel- 
ected— one  located  directly  across  Atlantic 
Avenue  from  South  Station,  and  one  located 
in  the  middle  of  the  rail  yards  behind  the 
South  Postal  Annex. 


Figure  18 


Measured  CO  Levels,  (PPM) 
South  Area 


1-hour    8-hour 


National  Ambient  Air 

Quality  Standard 


35 


South  Station  Site 

October 

6.3 

5.1 

November 

11.9 

7.4 

December 

11.3 

7.5 

Rail  Yards  Site 

• 

October 

7.1 

6.5 

November 

14.3 

9.1 

December 

8.9 

6.1 

Air  Quality  Technical  Support  Document 
to  the  Environmental  Impact  Report — South 
Station  Urban  Renewal  Project,"  ERT,  Inc 
May  1975. 


60 


Continuous  measuremants  of  CO  concentration,  . 
•vind  speed,  and  wind  direction  were  recorded 
over  a  three-month  period  (October-December 
1974).  Figure  18  presents  the  highest  1-hour 
and  8-hour  CO  concentrations  recorded  at  the 
2  sites  in  each  of  three  months,  and  compares 
them  with  the  National  Ambient  Air  Quality 
Standards  established  for  Carbon  Monoixde. 

The  results  of  the  measurement  program  suggest 
that  the  1-hour  CO  standard  is  not  likely  to 
be  exceeded  unless  conditions  in  the  area 
change  dramatically  as  a  result  of  the  pro- 
posed project.   Such  a  radical  change  in  traf- 
fic volumes  or  roadway  configuration  is  not 
anticipated.   The  8-hour  standard  was  ex- 
ceeded once  during  the  measurement  period, 
however,  and  is  probably  the  critical  stand- 
ard to  consider  in  analyzing  air  quality  im- 
cacts  of  proposed  South  Area  changes. 


II. D. 2     Noise 


The  noise  climate  along  the  South  Section, 
as  along  the  entire  length  of  the  Central  Ar- 
tery, is  created  primarily  by  the  dens6  city 
traffic  which  traverses  the  area,  both  on  the 
Artery  itself  and  on  local  streets  and 
arterials  in  the  vicinity  of  the  Artery.   The 
expressway  is  already  depressed  and  covered 
through  about  1/3   the  length  of  the  South 
Section.   Traffic  flowing  through  this 
tunnel  section  is  still  audible  to  an  ob- 
server standing  near  an  entrance  or  exit 
ramp  on  the  pavement  above.   It  contributes  to 
background  noise  level,  but  it  does  not 
represent  a  source  of  obvious,  intrusive  noise 
levels  above  the  background  at  these  loca- 
tions. Nevertheless,  peak  noise 
levels  in  areas  where  the  expressway  is  de- 
pressed tend  to  be  as  high  as  those  where  the 
road  is  at  or  above  ground  level.   This  is 
because  the  Artery  is  only  one  of  a  multit- 
ude of  major  noise  sources,  which  taken  to- 
gether, create  the  background  noise 
characteristic  of  such  noisy  urban  situa- 
tions that  changes  in  the  source  strength 
(e.g.,  traffic  volumes,  speeds)  or  the  geo- 
metric configuration  (e.g.,  elevated,  de- 
pressed of  any  one  source  tend  to  produce 
little  variation  in  the  overall  noise  level 
provided  the  other  noise  sources  ramain  un- 
changed.) In  addition  to  traffic-generated 


noise,  industrial  activities  associated  with 
the  nearby  rail  yards,  the  South  Postal  Annex 
operations  and  other  activities  in  the  Fort 
Point  Channel  area  contribute  substantially 
to  relatively  high  areawide  noise  levels. 

Where  the   expressway  is  visible  in  the 
South  Area,  it  tends  to  be  bordered  by 
high-rise  office  buildings,  industrial  uses, 
or  vacant  or' undeveloped  land.   During  the 
daytime,  especially  during  the  morning  and 
evening  peaks,  traffic  on  local  streets 
and  surface  arterials  is  the  predominant 
contributor  to  ambient  noise  at  the  first  - 
and  second-story  levels  of  most  buildings. 
This  is  because  the  local  streets  are  much 
closer  to  observers  on  the  first  several 
floors  than  is  the  expressway.   At  higher 
levels  of  multi-story  buildings  abutting 
the  unshielded  right-of-way,  the  effect  of 
the  higher  traffic  volumes  on  the  Artery  be- 
comes more  important.   At  night,  traffic  on 
local  streets  tends  to  decrease,  so  that 
expressway  traffic  noise  is  dominant  at  all 
levels  of  adjacent  buildings.   The  impor- 
tance of  this  is  mitigated  by  the 
fact  that  almost  all  nearby  buildings  are 
business  or  industrial  locations,  air  con- 
ditioned during  the  daytime  (i.e.,  having 
closed  windows)  and/or  unoccupied  at  night. 

In  general,  it  can  be  said  that  existing 
noise  levels  in  the  South  Area  are  quite 
high;  however,  they  are  not  unusual  or  in- 
appropriate for  an  urban  industrial/commer- 
cial location.   The  surrounding  land  uses 
tend  to  be  relatively  insensitive  to  what 
might  constitute  severely  annoying  noise 
levels  in  a  residential  or  suburban  loca- 
tion.  The  only  area  potentialy  sensitive 
to  changes  in  noise  climate  resulting  from 
modifications  to  the  Artery  in-  the  South 
Area  is  the  large  Chinese  residential 
community  located  west  of  the  Artery,  dir- 
ectly adjacent  to  the  interchange  with  the 
Massachusetts  Turnpike. 

The  niamerical  measurement  of  highway  noise 
is  done  in  terms  of  the  dBA  (decibel)  scale, 
which  measures  sound  intensities  in  such  a 
manner  as  to  weight  frequency  according  to 
its  magnitude  relative  to  the  varying  thresh- 
olds of  human  perception.  Empirically,  the 
dBA  scale  has  been  found  to  correlate  well 
with  human  response  to  typical  traffic  envir- 
onments.  To  give  an  indication  of  how  sound 


62 


levels  relate  to  dBA,  60-dBA  is  a  normal  in- 
door background  sound  level,  7  0-dBA  is  equiv- 
alent to  a  vacuum  cleaner,  and  8  0-dBA  is  about 
the  sound  level  of  a  garbage  disposal. 
It  is  important  to  note  that  the  dBA  scale 
is  a  logarithmic  rather  than  a  linear  measure 
of  sound  intensity.   Consequently,  a  10- 
dBA  sound  level  increase  denotes  a  factor  of 
ten  higher  intensity,  while  a  2-  dBA  increase 
denotes  a  factor  of  one-hundred. 

The  U.S.  Department  of  Transportation., in  its 
Policy  and  Procedures  Memorandim  90-2,  has 
established  noise  standards  relating  high- 
ways to  specific  adjacent  land  use  activit- 
ies.  These  standards  specify  that  the  de- 
sign noise  level  for  residential  areas  should 
not  exceed  70  dBA  outside  the  residences,  and  ■ 
that  the  exterior  noise  levels  for  developed 
lands  such  as  downtown  areas ,  should  not  ex- 
ceed 75-dBA.   In  the  following  discussion, 
noise  is  considered  in  terms  of  the  dBA 
levels  experienced  10%  of  the  time,  50%  of 
the  time,  and  90%  of  the  time,  respectively 
denoted  as  LlO,  L50,  and  L90. 

Measurements  of  existing  noise  levels  in 
the  South  Area  Corridor  were  made  as  part 
of  two  rtcent  studies:  the  1975  Central  Ar- 
tery Feasibility  Study  undertaken  by  the 
Boston  Redevelopment  Authority,  and  the  197  6 
South  Station  Urban  Renewal  Project  Environ- 
mental Impact  Report.   Figure  19  describes 
seven  measurement  sites  located  in  the  south 
Area,  and  presents  the  LlO,  L50,  and  L90 
noise  levels  for  those  sites  as  reported  in 
either  of  the  two  studies. 

There  are  two  noteworthy  aspects  of  the  meas- 
urement data.   The  first  is' that  the  consis- 
tently high  LlO  noise  levels  exceed  the  fed- 
eral design  noise  standard  for  residential 
areas  in  all  cases,  and  for  developed  areas 
in  more  than  half.   The  second  is  that  noise 
level  fluctuations  are  relatively  small. 
Only  in  one  case  is  the  difference  between  the 
reported  LlO  and  L90  level  greater  than  ten 
decibels.   These  findings  demonstrate  that  a 
high  "noise  floor"  or  ambient  noise  level, 
exists  throughout  the  South  Area,  created  by 
a  multitude  of  sources.   Modifications  to 
any  single  one  of  them  including  the  Central 
Artery,  will  probably  not  produce  significant 
overall  changes. 


c; 


Figure  19-  MEASURENEXTS  OF  EXISTING  NOISE  LEVELS, 
1975  and  1976 

Time      Measured 
of   Noise  Levels, dBA 
Day    LIO   L50   L90 


Location 


1.  Atlantic  Ave.,  between  Dewey 
Sq. ,  §  Essex  St.  * 

2.  Pedestrian  walkway  over 
Expwy.  before  tunnel  ent. 
at  Congress  St.  * 

3.  Congress  St.  over  tunnel 
entrance  between  Atlantic 
Avenue  §  Purchase  St.  * 

4.  Bridge  over  Fort  Point 
Channel  on  Congress  St.  * 

5.  Hotel  Essex,  facing 
Atlantic  Ave.** 

6.  Kneeland  St.  §  Atlantic 
Avenue  ** 

7.  South  Station  -southern 
end  of  rail  yard  ** 


8:00AM 

74 

70 

66 

8:30AM 

82 

79 

76 

7:20AM 

78 

73 

70 

7:20AM 

72 

66 

62 

4-4 :30PM 

76 

72 

67 

10-12  AM 

77 

68 

66 

6-8 :30AM 

72 

66 

65 

^Source: 


**Source: 


Memo  from  Klaus   Kleinschmidt,   Cambridge 
Acoustical  Associates,    to  David  Wallace,.  Wallace, 
Floyd,   Ellenzweig,   Moore  Inc.,   re  Central  Artery 
Noise  Survey,   April   26,    1977. 

"Noise  Analysis  Technical  Support  Document 
to  the  Environmental   Impact  Report — South 
Station  Urban  Renewal  Project",   prepared  by 
Environmental   Research   &  Technology  Inc., 
May  1976. 


II. D. 3  Water   Quality 

The   Central  Artery  South   Section   has   an 
impact  on  water   quality   both   as    it  exists 
today,    and   as    it  might  be   reconstructed   in 
the   future.      At  present,    runoff   from  the  Ar- 
tery drains   primarily   into   the  Boston  main 
drainage   system,   which   is   a  very  old   combined 
sytem  with   interceptor   sewers   along   the  water- 
front.     These   interceptors   discharge   into   the 
MDC  main  drainage   tunnel  which   in   turn   leads 
to   the  Deer   Island   treatment   facility   in 
Boston  Harbor.      Trunk   sewers   from   the   collec- 
tion  system  discharge  dry  weather   flows    into 
these   interceptors    through   regulators.      Storm 
flows,    however,    pass   directly   into   Fort   Point 
Channel   and   the   harbor   through   tide-gated 
outlet   structures. 


64 


The  City  of  Boston  has  proposed  construc- 
tion of  increased  capacity   interceptor  se- 
wers, including  a  new  Fort  Point  Channel  Inter- 
ceptor, to  be  located  on  the  west  side  of  the 
channel.   A  197  5  study  recommended  a  decen- 
tralized overflow  system  including  a  Fort  Point 
Channel  facility  that  would  connect  all  dis- 
charge locations.   As  yet,  none  of  the  pro- 
posed facilities  have  reached  the  point  of 
nrogramming  for  implementation,  nor  have 
final  designs  for  the  facilities  been  drafted. 
As  such,  runoff  from  the  Central  Artery  and 
other  downtown  streets  will  continue  to 
discharge  untreated  into  Fort  Point  Channel 
and  Boston  Harbor  during  storms  for  some 
time  into  the  futoixe. 

Potential  future  Central  Artery  construction 
has  further  impacts  related  to  water  quality, 
because  the  split  alignment_option  could 
have  a  highway  tunnel  built'within  the  Fort 
Point  Channel  itself.   Such  construction  would 
impact  the  bed  of  the  channel  which  today  is 
recognized  as  having  among  the  most  fouled 
conditions  of  any  part  of  the  Boston  Harbor 
bottom.   Previous  studies  have  observed  and 
sampled  sludge  deposits  in  the'  Fort  Point 
Channel  of  more  than  three  feed  thickness , 
containing  oily  residues  and  emitting  foul 
odors . 8  Oily  muck  completely  paves  the  Fort 
Point  Channel  to  a  minimum  depth  of  six 
inches.   Absolutely  no  marine  life  is  present. 
Measurements  of  water  quality  indicare  that 
the  surface  water  is  grossly  polluted  as  a 
result  of  storm  water  discharges  and  poss- 
ibly by  continuing  dry  weather  flows  as  well. 

With  these  problems,  it  is  apparent  that 
potential  construction  in  the  Fort  Point 
Channel  may  offer  an  opportunity  to  remove 
polluted  sediments.   Obviously,  such  re- 
moval will  have  to  be  done  with  care  taken 


7  Eastern  Massachusetts  Metropolitan  Area 
Wastewater  Engineering  and  Management  Plan 
for  Boston  Harbor,  prepared  by  Metcalf  and 
Eddy  for  the  U.S.  Corps  of  Engineers  and  the 
Massachusetts  District  Commission,  1975. 

Q Biological  Aspects  of  Water  Quality-Charles 
River  and  Boston  Harbor,  Mass.,  performed  by 
the  Federal  Water  Pollution  Control  Adminis- 
tration of  the  U.S.  Department  of  the  Interior, 
1967. 


65 


to  ensure  that  undue  further  dispersal  of 
old  sediments  does  not  take  place.   Combined 
with  interceptor  sewer  construction,  building 
of  a  highway  facility  in  Fort  Point  Channel 
could  offer  the  opportunity  to  marke  lly 
improve  one  of  the  worst  pollution  problems 
in  the  Boston  Harbor  area. 


Figure  20:   Boston  Harbor  Water  Quality  Survey 
Station  #39  -  Fort  Point  Channel 
CMouth  of  Channel) 


Sample  No. 

R54939 

R55111 

R55471 

R55715 

R55878 

Date  of  collection 

6/20/72 

7/18/72 

8/15/72 

9/12/72 

10/17/7: 

Time  of  collection 

2:20pm 

10:55am 

11:40am 

10:15am 

10:25am 

Temperature,  deg  F 

- 

- 

- 

- 

56 

Low  Tide 

1 : ISpm 

11:37am 

10:07am 

8:47am 

12 :  24pni 

BOD 

2.8 

2.7 

3.4 

2.6 

2.8 

pH 

7.8 

7.6 

7.7 

7.7 

7.7 

Alkalinity-Total 

84 

108 

102 

107 

103 

DO 

3.8 

6.2 

6.2 

1.3 

4.2 

Chlorides 

10,800 

14,000 

15,000 

15,400 

Total  solids 

- 

- 

- 

- 

- 

Susp.  solids-Total 

6.5 

1.5 

- 

1.5 

1.0 

Loss 

- 

- 

- 

- 

- 

Total  P 

0.30 

0.16 

0.10 

0.18 

•0.18 

Coliform-Total 

460,000 

150,000 

24,000 

- 

240,000 

Fecal 

460,000 

93,000 

2,400 

- 

93,000 

Color 

45 

20 

15 

18 

10 

Turbidity 

1 

1 

1 

1 

0 

Total-Kj-N 

2.2 

1.0 

- 

- 

- 

Ainmonia-N 

0.38 

0.5 

0.31 

0.26 

0.38 

Nitrite-N 

- 

- 

- 

- 

- 

Nitrate-N 

0.1 

0.0 

0.0 

0.0 

0.0 

Source:   Commonwealth  of  Massachusetts,  Division  of 

Water  Pollution  Control,  Metropolitan  Regional 
Office,  Apri'l,  1975. 


66 


CHAPTER   III:    ALTERNATIVES    FOR    IMPROVEMENT 

During  the  past  two  decades,  numerous 
plans  have  been  proposed  for  improving 
the  Artery.   Some  improvements  have 
been  implemented,  but  most  of  the  plans 
have  become  documents  for  library 
shelves.   Numerous  studies  for  major 
improvements  of  related  projects  have 
also  been  undertaken,  often  without 
reference  to  the  manner  in  which  the 
Artery  operates  as  part  of  a  larger 
system  of  transportation  service. 

III. A    PAST  EFFORTS 

Previous  studies  on  the  South  Area  of  the 
Artery  corridor  have  been  numerous.   They 
are  summarized  in  Appendix  I.   The 
general  trend  of  past  studies  has  been  to 
add  facilities  to  the  existing  network, 
without  altering  the  pattern  of  the 
present  highway  facilities.   These  studies 
have  been  summarized  below  in  two  groups- 
alternatives  outside  the  present  Artery 
corridor,  and  alternatives  within  the 
present  corridor. 

III.A.l   Alternatives  outside  the  Artery  Corridor 

There  have  been  several  concepts  for 
bypassing  the  Artery  completely  in  order 
to  avoid  the  difficult  problems  of 
serving  both  local  and  through  traffic 
on  the  same  facility.   These  have  been 
dropped  from  further  consideration  for 
various  reasons.   The  alternatives  are 
as  follows:   (See  Figure  21) 

A^ The  Inner  Belt 


The  philosophy  of  a  radial  expressway 

and  inner  belt  highway  system  was  presented 

in  the  Master  Plan  for  Highways  in  the 

Boston  Metropolitan  Area  in  1948,  and 

was  adopted  by  the  Commonwealth  as  a 

basis  for  long-range  improvement  to 

area  highways.   The  Central  Artery  was 

a  portion  of  the  Inner  Belt  under  this 

plan. 

The  basic  functions  of  the  Inner  Belt  were: 
(a)   to  serve  as  a  collector-distributor  of 
traffic  in  the  Core  Area  and  (b)  to 
interconnect  radial  expressways  for  traffic 


67 


with  an  origin  or  destination  either ^in 
metropolitan  Boston  or  on  any  part  of  the 
interstate  highway  system. 

As  a  partial  result  of  this  plan,  the 
Central  Artery  was  constructed.   To 
complete  the  Belt,  a  series  of  30  al- 
ternatives were  studied  and  10  were 
examined  in  detail.   However,  in  1971, 
Governor  Sargent  made  the  decision 
not  to  proceed  with  further  plans  for  the 
Inner  Belt,  for  these  major  reasons: 

a.  Extensive  residential  takings  in 
Somerville  and  Cambridge  and  inability 
to  meet  the  relocation  requirements , 
which  had  become  more  stringent  since 
initial  plans  were  put  forth. 

b.  Major  disruption  to  communities 
along  the  corridor  of  the  proposed 
highway,  to  which  local  municipal 
officials  had  become  opposed. 

c.  Community  protest  over  the  scale, 
location,  impacts  and  costs  of  the  propos.ed 
Inner  Belt. 

d.  Technical  questions  resulting 

from  re-examination  of  the  traffic  projec- 
tions and  the  ability  of  connecting  radials , 
including  the  Central  Artery  to  accomodate 
projected  volumes  and  movements. 

e.  Increased  highway  construction  was 
considered  to  be  counterproductive 
because  it  would  generate  traffic  for  the 
core  area  of  Boston,  which  cannot 
accommodate  present  traffic  and  parking 
demands . 

Since  the  Governor's  decision,  funds 
previously  allocated  to  the  Inner  Belt 
have  become  part  of  the  Massachusetts 
Interstate  Transfer.   In  addition,  the 
Commonwealth's  transportation  policy  and 
decisions  about  specific  facilities 
have  reinforced  the  determination  that 
the  Inner  Belt  is  no  longer  a  feasible, 
desirable  or  prudent  alternative,  nor 
is  it  politically  acceptable. 


68 


A.  INNER   BELT 

a.  OUTER    HARBOR   CROSSINO 
C.  CHELSEA-  EAST  BOSTON  BYPi 
a  PIER-TIP  ALIGNMENT 
E.CROSS- BOSTON    TUNNEL 


ALTERNATIVES  TO  THE  ARTERY  CORRIDOR 


Figure   21 


65 


B.  Outer  Harbor  Crossing 

As  early  as  the  1930 's,  a  highway  to  connect 
between  Route  1-A  on  the  north  and  the  area 
south  of  the  core  was  examined.   This  was 
later  reviewed  and  studied  by  the  Boston 
Transportation  Planning  Review  as  a 
connection  between  Route  1-A  and  the  South- 
east Expressway.  The  proposed  facility 
used  the  harbor  islands  for  its  route,  through 
a  combination  of  bridges  and  surtace 
facilities.   A  major  crossing  of  the 
shipping  channel  leading  to  and  from 
Boston  Harbor  was  included.   While  the 
alternative  of  a  tunnel  was  suggested 
for  this  crossing,  problems  of  interference 
with  the  shipping  channel  along  with 
anticipated  costs  of  construction 
precluded  it  from  further  consideration. 
The  proposed  bridge  was  similarly 
difficult;  under- clearance  requirements 
for  shipping  made  the  bridge  height  a  hazard 
for  Logan  Airport  flight  path  clearance 
standards.   In  addition  the  proposed 
approach  roads  would  have  violated 
Section  4(f)  provisions  in  utilizing 
islands,  wetlands  and  publicly  owned  land 
along  the  proposed  alignment. 

While  this  alternative  would  have  provided 
connections  for  two  major  expressways  and 
a  bypass  for  the  Central  Artery,  it  did  not 
provide  connections  and  distribution  to 
the  various  sections  of  the  region,  and 
it  did  not  provide  adequately  for 
downtown  collection  and  distribution. 
Access  to  the  airport  was  also  constrained 
by  the  need  for  interchange  of  traffic 
in  either  the  residential  or  open  space 
areas  of  East  Boston.   While  it  may  well 
have  resulted  in  new  origins  and 
destinations  it  did  not  address  the 
problem  of  the  existing  traffic  overloads 
on  the  Central  Artery,  as  traffic  was  not 
diverted  from  the  Artery. 

C.  Chelsea-East  Boston  Bypass 
Another  alternative  investigated  in  1971 
was  a  downtown  bypass  from  1-93  on  the 
north,  through  Chelsea  to  East  Boston  and 
the  airport  and  in  a  tunnel  under  the 
harbor,  to  connect  to  the  Southeast 
Expressway-Mass  Pike  interchange  at  the 
south  edge  of  downtown.   This  alternative 
was  conceived  as  part  of  plans  then  being 
considered  for  1-95  north  through  Lynn, 


70 


and  1-95  relocated  through  East  Boston 
and  Revere.   It  was  intended  to  address 
the  problem  of  how  traffic  on  the  north 
from  both  1-93  and  proposed  1-95  could 
get  access  to  the  airport  and  around 
downtown  for  non-core  destinations.   The 
bypass  was  also  directly  related  to  a 
proposed  general  purpose  third  harbor 
crossing  between  East  Boston  and  the 
Fort  Point  Channel  area  in  South  Boston, 
and  in  fact  incorporated  this  tunnel 
as  a  major  element  of  its  alignment. 

Early  analysis  of  this  alternative  showed 
that  the  proposed  alignment  had  a  nximber 
of  major  problems  of  feasibility.   The 
proposal  would  have  required  either  a 
new  alignment  or  a  narrow  rail  right-of- 
way  in  the  Everett/Chelsea  area  which 
would  have  caused  substantial  residential 
property  takings  and  impacts  on  local 
neighborhoods.   The  Chelsea  Creek 
crossing  was  complicated  by  the  need  to 
retain  shipping  access  to  the  oil 
terminals  located  at  the  head  of  the  creek. 
In  East  Boston,  major  conflicts  with 
expressway  and  local  circulation,  along 
with  substantial  impacts  on  the  adjacent 
residential  community  were  also  found.   The 
location  through  either  East  Boston  or  the 
airport  was  another  major  problem.   This 
was  later  resolved  by  a  decision  to  use 
airport  property  for  connections  to  the 
proposed  third  harbor  crossing.   Because 
of  impacts  of  this  alignment,  longer 
tunnels  were  discussed,  but  the  costs  and 
potential  impacts  were  prohibitive.   In 
addition,  because  of  the  lack  of  direct 
connection  to  1-93,  the  over-capacity 
traffic  conditions  on  the  Central  Artery 
would  have  remained. 

After  preliminary  analysis  and  strong 
community  objections  to  the  alignment, 
this  proposal  was  dropped.   Its  dependence 
on  1-95  through  Lynn,  and  relocated  1-95 
through  East  Boston  and  Revere  became 
apparent,  and  both  of  these  alternatives 
were  dropped  from  further  consideration 
by  the  Commonwealth.   The  third  harbor 
crossing  portion  of  the  alignment  remained 
as  a  viable  portion  of  the  proposed 
connection  -  not  as  a  bypass  of  the  Central 
Artery,  but  for  service  directly  to  and 
from  the  airport. 


71 


D.   Pier-Tip  Bypass 

After  analysis  of  alternatives  outside 
the  main  core  area  of  Boston,  other 
alignments  closer  to  downtown  were 
investigated.   A  pier-tip  bypass  was 
proposed,  connecting  between  the  junction 
of  the  Mystic  Bridge  and  1-9  3  on  the 
north  and  the  junction  of  the  Mass.  Pi!:e 
and  the  Southeast  Expressway  on  the 
south,  and  using  the  harbor  bottom  as  the 
right-of-way  along  the  ends  of  the 
downtown  piers.   The  alternative's 
advantages  were:   (a)  construction 
of  a  new  facility  without  disturbing 
traffic  in  the  heart  of  the  city;  (&) 
a  right-of-way  which  would  be  "free" 
and  which  would  afford  relative  ease 
of  construction;  (c)  the  potential 
for  separation  of  local  and  through 
traffic  with  the  existing  Artery 
retained  for  the  collection  and 
distribution  of  traffic  in  downtown 
Boston. 

However,  this  alternative  did  not 
address  the  problem  of  providing 
improved  access  between  major 
expressways  and  the  airport  because 
it:  could  not  connect  directly  with 
the  existing  tionnels  and  the  proposed 
third  harbor  crossing.   This  became 
a  major  deficiency,  because  the  pier- 
tip  tunnel  would  only  serve  north- 
south  through  traffic  and  not  meet 
major  demands  for  access  between 
expressways  and  either  the  airport 
or  downtown.   Problems  with  the 
physical  feasibility  included  grades 
of  the  connections  on  either  end, 
possible  interference  with  shipping 
in  the  harbor  during  construction, 
plus  the  logistical  problems  of 
constructing  a  long  tunnel  entirely 
under  water,  with  attendant 
difficulties  of  getting  approvals 
for  the  filling  required  to 
construct  the  tunnel. 

Because  of  its  prohibitive  costs  and 
environmental  impacts,  it  was  decided 
that  the  alternative  was  not  feasible, 
and  it  was  dropped  from  further  study. 


E.       Cross-Boston    Tunnel 

The   last  of   the   alternatives    that  would 
bypass    the    corridor  of   the   existing 
Central   Artery  was    a  proposal    advanced 
in    19  74    for   construction   of  a   deep-bore 
tunnel    to   connect  directly    from  the 
Mystic   Bridge    1-93   intersection   on 
the   north    to    the   Southeast  Expressway 
and  Mass.    Pike    interchange   on   the 
south.      The   elements   of   this   proposal 
included  an  additional   short   tunnel 
connecting   from  the   north   to   the   entrance 
of   the   Sumner/Callahan   Tunnels   on  an 
alignment  directly   under   the  existin  g 
Artery   to   serve   airport   traffic.      It 
was   proposed   that,    following  construction, 
the  Artery   could  be   removed   and   the 
corridor   used  as   a   major   arterial   street 
providing  access    to    downtown  locations. 

The   advantages   cited  included:       (a)    the 
length  of   the    tunnel,    which  would  be 
the   shortest  possible   connection  between 
major   regional   expressways;    (b)    construction 
would  not  be   entirely   in   the   Artery 
corridor    (other  alternatives   being 
considered  at   the   time   used  the   existing 
Artery   corridor   for  a  new   facility)  ;       (c) 
,  preliminary  examination   indicated   that 
overall   construction   impacts  would  be 
significant,    but  less    than   other 
alternatives. 

The   proposal   had  several   major  drawbacks: 
(a)    its   common  weakness    shared  with 
other  past  proposals   was    its    inability 
to   deal  with   the   role   of   the  Central 
Artery  as   a  downtown  collector  and 
distributor  of   traffic,    though   it  did 
have    the    advantage   of   exclusive   access 
to    the   Sumner/Callahan   Tunnels;     (b) 
the  proposed  arterial   street  could  not 
adequately  meet  existing  collection 
and  distribution   demands    in   the   downtown 
area.      It  would  have   produced  spillover 
traffic  on   local   streets,    with   impacts 
on  adjacent  residential   and  business 
areas;     (c)    there   are   serious   questions 
of   feasibility   that  a  highway   rising 
from  a   deep-bore   tunnel   across    downtown 
Boston   could  meet   the   necessary  vertical 
clearance    requirements    to   cross    the 
Charles    River  without  constructing  a 
massive,    multi-tiered  interchange   in 
the   North   Station   area;     (d)    sub-surface 


73 


conditions  in  the  area  of  the  proposed 
tiinnel  may  be  such  that  this  alternative 
is  technically  infeasible.   Construction 
problems  near  and  under  large  buildings, 
utilities  and  subway  tunnels  were  major. 
(e)  the  proposed  tunnel  would  have 
req\iired  installation  of  extensive  venti- 
lation equipment  to  meet  present  and 
future  air  quality  standards.    The 
location  of  ventilation  structures  and 
the  impact  of  the  exhaust  disposed  through 
ventilation  structures  would  have  produced 
.  major  negative  impacts  on  downtown.   For 
all  of  these  reasons,  this  alternative 
was  dropped  from  further  study. 

III. A. 2   Corridor  Retention 


The  analysis  of  alternatives  to  bypass  the 
corridor  of  the  present  Central  Artery 
has  been  instructive  on  several  points: 

1.  Alternative  alignments  for  the 
relocation  of  all  or  part  of  the 
present  functions  of  the  Artery 
cannot  be  easily  found. 
Alternatives  which  have  been 
presented  and  examined  in  some 
detail  have  the  disadvantages 

of  not  replacing  or  relocating 
the  functions  of  the  Artery, 
and  not  substantially  easing  its 
present  problems. 

2.  High  costs  are  incurred  in  all  of 
the  alternatives  to  the  present 
Artery  corridor,  both  in  terms 

of  funding  the  construction  and 
operations  on  adjacent  neighborhoods. 

3.  The  present  Artery  would  have  to  be 
retained  in  virtually  all  instances 
as  a  collection  and  distribution 
facility  for  d'owntown,  and  in  most 
instances  for  airport  access  via 
the  Sumner/Callahan  Txmnels  as  well. 

4.  Improvements  to  the  present  facility 
would  be  required  in  all  alternatives, 
Safety  considerations  and  the  aging 
structure  of  the  present  facility 
must  be  dealt  with  at  some  future 
date.   Simply  eliminating  the 
present  Artery  without  adequately 
providing  for  its  present  functions 

is  not  a  solution  to  transportation 
needs . 


74 


5.     All  of  the  alternatives  to  the 

present  Artery  tried  to  find  means 
of  avoiding  the  problems  associated 
with  construction  of  a  new  facility 
in  the  present  Artery  corridor  while 
maintaining  traffic.   However, 
the  present  corridor  of  the  Central 
Artery  is  the  only  alignment  which 
affords  all  the  advantages  of 
connections  between  the  radial 
regional  expressway  network.   In 
addition,  it  is  the  only  alignment 
which  provides  collection  and 
distribution  into  the  regionally 
important  downtown  area.   It  thus 
appears  that  the  present  Artery 
corridor  must  be  retained  for  these 
functions . 

^*    Transit  options  cannot  perform  the 
functions  provided  by  the  Artery. 


III.B    ALTERNATIVES  WITHIN  THE  PRESENT  CORRIDOR 


The  South  Area  of  the  Artery  Coirridor 
contains  highly  valued  land  areas  and 
neighborhoods  which  form  major  constraints 
on  the  selection  of  alternatives  for 
improvement  to  the  highways  in  the 
area.   At  the  same  time,  these  areas 
define  the  corridor  locations  in  which 
opportunities  are  presented  for  highway 
improvements.   Because  of  the  efforts  . 
already  underway  to  preserve  and 
enhance  several  of  these  areas  they 
have  been  listed  below  as  the  setting 
for  further  examination  of  alternatives. 

III.B. 1   South  Area  Highway  Planning  Context 

Each  of  the  efforts  listed  below  is 
identified  on  Figure  22  by  the  nximerical 
designation  which  appears  in  the  text. 

1.   Waterfront  Urban  Renewal  Project 
The  bulk  of  this  project  falls  in  the 
Central  Area  of  the  corridor,  but 
several  of  the  South  Area  improvements 
would  affect  development  and  parcels  in 
the  southerly  portion  of  the  project 
area.   Specifically,  this  area  includes 
the  Harbor  Towers  apartment  development 
and  several  waterside  parcels  not  yet 
developed. 


75 


2.  The  Fan  Pier  -  Athanas  Properties 
A  large-scale  private  development  on 
the  Fan  Pier  and  adjacent  waterfront 
lands  has  been  discussed;  plans 
include  apartment  and  marina  activities. 

3.  Town  and  City  Properties,  Ltd. 
Many  of  the  existing  structures  - 
principally  large  warehouse  structures  - 
are  planned  for  rehabilitation  for 

new  commercial  uses.  The  redevelopment 
of  the  area  is  already  in  progress  with 
some  small-scale  rehabilitation. 

4.  Railroad  Properties 

This  land,  recently  offered  for  sale 
by  the  Penn  Central  Railroad  Company, 
is  largely  vacant,  with  some  residual 
railroad  uses.   Part  of  the  area  is 
scheduled  for  transportation  improvements, 
including  the  re-aligned  Northern  Avenue 
approaches  to  a  new  Fort  Point  Channel  bridge ^ 

The  riqht-of-way  for  the  proposed 
Seaport  Access  Road  would  also 
potentially  use  portions  of  this  land. 

5.  Gillette  Company 

A  large  manufacturing  plant  for  the 
Gillette  Company  occupies  a  site  on  the 
Fort  Point  Channel.   This  plant  is  a 
chief  location  for  the  manufacturing  of 
razor  blades  and  associated  products. 

6 .  Cabot  Yards 

The  MBTA  has  constructed  a  new  facility 
for  the  maintenance  and  storage  of  its. 
Red  Line  rapid  transit  vehicles  on  this 
site.   The  facility  also  includes  a 
major  bus  storage  and  maintenance  area. 

7.  South  Station  Transportation  Center 
Major  plans  for  this  site  have  been 
developed  to  construct  a  multi-modal 
transportation  interchange  facility, 
which  will  include  intercity  rail  and 
bus,  rail  and  bus  commuter  lines  and 
parking - 

8.  Lafayette  Place 

This  area  has  been  designated  for  new 
commercial  development,  including 
expansion  of  the  area  occupied  by 
the  Jordan  Marsh  department  Store, 
and  additional  commercial  space  to  be 


76 


RELATED  PLANNING    EFFORTS 


Figure  22 


constructed  adjacent.   Street  changes 
include  a  new  Essex  Street  which  will 
connect  directly  with  the  Artery 
corridor. 

9.   Chinatown 


The  long-established  Chinese  community 
is  based  in  this  area.   Shops, 
apartments  and  cultural  facilities 
continue  this  focus.   a  new  school 
and  new  apartments  have  strengthened 
the  community  in  recent  years . 

10 .  South  Cove  Urban  Renewal  Area 
This  project  has  provided  space  for 
the  expansion  of  the  Tufts-New  England 
Medical  Center  and  includes  the  small 
community  known  as  Bay  Village. 

11.  Park  Plaza 

Recent  'city  efforts  have  led  to  a  plan  for 
a  multiple  use  area  which  will  include 
retail  activities,  government  and  private 
offices  and  apartment  units. 

12.  South  End  Urban  Renewal  Area 
This  large  neighborhood  has  been  the 
location  of  major  urban  renewal  efforts 
over  the  past  years.   Many  of  these 
efforts  have  been  directed  toward 
strengthening  the  residential  character 
of  the  area.   Both  public  and  private 
efforts  have  resulted  in  the  restoration 
of  structures  and  the  enhancement  of 
the  comm;inity. 

13.  South  Bay 

This  area  is  the  location  of  a  new 
maintenance  facility  constructed  by  the 
City  of  Boston,  and  is  the  site  of  the 
Wholesale  Food  Market.   Residual 
railroad  facilities  are  also  found  here. 

14.  South  Boston 

This  area  is  a  stable  residential 
community  which  contains  manufacturing 
and  shipping  concerns.   Truck  traffic 
on  residential  streets  is  being 
addressed  through  planning  of  the 
Seaport  Access  Road. 

15.  Musexjm  Wharf 

This    location   is    the   new  home  of    the 
Children's   Museum  and   the  Museum  of 
Transportation.      A   former  wharf 


building,  it  will  be  rehabilitated 
for  museum  use  and  will  be  partially 
opened  in  the  fall  of  1978. 

III.B.2  Derivation  of  Alternatives 

Land  uses  and  proposed  community  improvements 
were  examined  in  conjunction  with  transportation 
problems  in  the  South  Area  of  the  Central 
Artery.   Constraints  imposed  by  the  need  to 
plan  improvements  within  the  existing 
corridor  and  to  minimize  impacts  on  surround- 
ing areas  led  to  two  classes  of  alternatives. 
The  first  group  provides  for  improvements 
along  the  present  alignment.  This  includes 
the  no-build  option,  wiaening  of  the  pres- 
ent Dewey  Square  Tunnel  and  double-aecking. 
In  all  cases,  traffic  in  both  directions 
would  continue  to  use  the  present  align- 
ment with  proposed  modifications. 

The  second  class  of  alternatives  would 
split  the  alignment  in  the  Dewey  Square  por- 
tion of  the  corridor,  with  southbound 
traffic  using  the  present  Dewey  Square 
Tunnel  and  northbound  traffic  using  a  new 
alignment  in  one  of  two  possible  loca- 
tions :  under  either  Atlantic  Avenue  or 
the  Fort  Point  Channel.   In  order  to  narrow 
alternatives,  each  of  these  groups  were 
analyzed  in  some  detail. 

III.B.2. a   Improvements  along  the  Present  Alignment 


This  set  of  improvement  options  centers 
on  the  existing  Dewey  Square  Tunnel. 

1.   No  Build  - 


In  this  option  the  existing  facility  is 
retained  and  modified  as  necessary  to 
accomodate  minor  improvements  for  traffic 
service  and  safety.   Traffic  capacity  and 
design  standards  would  remain  the  same  as 
they  now  are.   Deck  rebuilding  would  be 
required  south  of  the  Dewey  Square  Tunnel 
because  the  decks  are  approaching  the  end 
of  their  useful  life. 

2.   Widening  of  the  Dewey  Square  Tunnel  - 
Several  possibilities  exist  for  widening, 
and  range  from  modest  improvements  to  break- 
down and  speed  change  lanes  to  the  addition 


79 


of  new  lanes  for  carrying  traffic.   If  new 
lanes  are  added,  they  must  be  located  out- 
side the  existing  tunnel  on  one  or  both 
sides,  with  traffic  reallocated  between 
existing  and  new  facilities.   South  of  the  Dewey 
Square  Tunnel,  the  viaduct  would  consist  of  3 
lanes  in  each  direction,  with  shoulders  used  in 
peak  periods  to  accommodate  traffic  demand. 

3.   Double  Decking  the  Present  Facility  - 
This  option  would  create  an  additional 
level  of  highway  on  a  viaduct  over  the  sur- 
face street  which  is  now  above  the  Dewey 
Square  Tunnel.   Capacity  of  the  South  Area 
would  be  increased  and  the  tunnel  would 
no  longer  act  as  a  bottleneck  for  traffic 
because  it  would  only  carry  southbound 
traffic  and  the  new  viaduct  only  north- 
bound ,traff ic. 

Each  of  these  options  for  improvements  along 
the  present  alignment  has  been  examined  for 
feasibility  and  adaptability  to  the  Artery 
setting.   The  No  Build  option  must  be  carried 
forward,  not  only  because  it  may  in  fact  be 
a  reasonable  solution,  but  also  because 
it  provides  the  base  case  for  analysis  of 
other  options.   Widening  also  can  be  re- 
tained, as  a  possible  cost  saving  approach 
to  solving  certain  of  the  Dewey  Square 
Tunnel  problems.   However,  preliminary 
analysis  indicates  that  impacts  from  widen- 
ing of  the  present  facility  are  severe  for 
adjacent  communities  and  would  be  unaccept- 
able to  them.   Selective  widening  of  modest 
proportions  can  be  examined  for  specific 
locations  where  operational  problems  can 
be  solved  by  modifications  to  speed  change 
lanes  or  by  adding  breakdown  bays.   Such 
improvements  would  be  part  of  the  No  Build 
option. 

Double  decking  would  be  unacceptable  to  the 
communities  nearby  and  would  extend  the 
blighting  influence  of  the  existing  via- 
ducts into  the  Dewey  Square  area .   The  de- 
sign of  links  between  the  new  upper  deck 
and  the  existing  facilities  would  also  be 
difficult  to  achieve  without  substantial 
environmental  impacts  and  would  disrupt 
traffic  during  the  construction  period. 
For  these  reasons,  double  decking  has  been 
dropped  from  further  consideration. 

III.B.2.b   Split  Alignment  Alternatives 


This  set  of  improvement   possibilities 
centers  on  the  use  of  both  an  improved 
8Q       Dewey  Square  Tunnel  for  southbound 


traffic  and  a  new  facility  parallel  to 
the  tunnel  for  northbound  traffic.  This 
new  facility  could  be  located  in  one  of 
two  locations  -  either  the  Fort  Point 
Channel  or  Atlantic  Avenue. 

1.  Fort  Point  Channel  Split  Alignment 
This  option  would  have  a  new  northbound 
tunnel  in  the  Fort  Point  Channel  -  parallel 
to  the  existing  Dewey  Square  Tunnel  which 
would  serve  southbound  traffic.   The  new 
tunnel  would  begin  at  the  Turnpike  inter- 
change and  extend  in  the  Channel  to  join 
the  existing  Central  Artery  right-of-way 

in  the  vicinity  of  the  Northern  Avenue 
Bridge.   By  adding  new  capacity,  this  op- 
tion would  relieve  the  present  constraint 
formed  by  the  Dewey  Square  Tunnel.   Design 
geometries  of  both  the  Dewey  Square  Tunnel 
and  the  new  roadway  would  be  improved  to 
meet  acceptable  standards.   This  right-of- 
way  affords  ease  of  construction  because 
of  a  relatively  clear  alignment,  without 
major  traffic  disruption  and  physical  re- 
straints imposed  by  existing  development. 

2.  Atlantic  Avenue  Split  Alignment 
This  option  is  similar  to  the  Fort  Point 
Channel  alignment  except  the  new  northbound 
txinnel  would  be  located  under  Atlantic  Ave- 
nue.  The  new  tunnel  would  extend  from  the 
existing  right-of-way  at  the  Turnpike  inter- 
change under  the  rail  yard  and  Atlantic  Ave- 
nue and  rejoin  the  present  Artery  near  Dewey 
Square.   Benefits  in  terms  of  geometries  and 
capacity  improvements  are  similar  to  the 
Fort  Point  Channel  alignment. 

This  option  is  more  difficult  to  construct 
because  it  must  pass  under  commuter  rail 
and  AMTRAK  lines  and  a  heavily  travelled 
street,  and  above  an  existing  rapid  transit 
station  at  South  Station.   It  also  must  pass 
through  a  narrow  right-of-way  at  Dewey  Square. 
The  constrained  right-of-way  makes  it  ex- 
tremely difficult,  if  not  impossible,  to  add 
a  transit  connection  between  North  and  South 
Stations  as  part  of  Central  Area  reconstruc- 
tion plans,  should  it  be  undertaken.   Never- 
theless, the  option  has  been  retained  for  more 
detailed  examination.   For  purpose  of  this 
discussion,  the  Atlantic  Avenue  alignment  is 
included  as  a  variation  of  the  Fort  Point 
Channel  Split  Alignment. 


81 


III.C         ALTERNATIVES    FOR   FURTHER   STUDY 


Based  on  the  previous   studies    in   this 
part  of   the  metropolitan  area   and   the 
constraints  which   limit  alternatives    for 
South  Area  highway   improvements,    several 
new   alternatives   have  been   identified  within 
the  context  of  other   proposed  highway 
improvements.      These  have  assisted   in   form- 
ulating potential   improvements    for   the 
South  Area. 


III.C. 1        Relationship  to  other  potential   projects 

In  the   densely  built-up  core   area,    it  is 
difficult  to   find  rights-of-way   for   new 
highways    to   improve   the   regional   network. 
It   is    the   Commonwealth's    policy   to   expand 
the   transit   network   for   core-oriented 
trips    and   to    improve  highway   service   for 
trips    that  cannot  be   served  by    transit. 
While   the   transit  network   can  be   expanded 
to   improve   the  regional   population's 
access   into   the   core  of   the  region,    it 
cannot  be   expected   to   displace   the   need 
for  maintaining  adequate  highway   service 
to   and  through   the   core. 

The   potential   projects  which    influence 
decisions    in   the  South  Area  of   the  Artery 
Corridor   are: 

1.  The  proposed   improvements   in   the 
Central  Area  of   the  Artery  Corridor. 

2.  The   proposed  third  harbor   tunnel 
between  downtown  and  Logan  Airport. 
If   constructed,    this   project  would 
connect  only   to  Logan  Airport.      It 
has    two   possible   forms   of   service: 

a.  A  special   purpose   tunnel, 
serving  only  buses,    trucks, 
taxis   and   emergency   vehicles 
to   and   from  the  airport. 

b.  A  general   purpose    tunnel 
serving  all    types   of  vehicles 
to   and  from  the  airport. 

3.  The   proposed  rail   connection  between 
North   Station  and  South   Station.      This 
proposal    is   applicable  only   to    the 
alternatives  which    link    to    the 
Central  Area  of   the  Artery  corridor. 


82 


III.Ci2   Separability  of  the  South  Area 


Proposed  improvements  in  the  South  Area  can 
take  place  either  in  conjunction  with  other 
improvements  or  as  separate  projects.   For 
purposes  of  analysis,  the  South  Area  has 
been  examined  as  a  single  project  -  for  both 
no-build  and  build  alternatives  -  and  in  con- 
junction with  other  related  projects.   This" 
has  produced  several  permutations  of  po-  ' 
teritiai  improvements  which  are  outlined  in 

figure  .21.^ 


Figure  23  South  Area  Alternatives 


Without 
3rd  H.C. 

With  3rd  Harbor  Crossing 

Special 
Purpose 

General 
Purpose 

NO  BUILD 

Alt.  1 

Alt.  2 

Alt.  3 

SPLIT  ALIGNMENT 
WITHOUT  CENTRAL 
AREA 

Alt.  4 

Alt.  5 

Alt.  6 

SPLIT  ALIGNMENT 
WITH  CENTRAL 
AREA 

Alt.  7 

Alt.  8 

Alt.  9 

III.C.3   Feasible  Alternatives 

Each  of  the  alternatives  included  in  the 
chart  above  has   been  examined  in  detail  to 
determine  system  and  traffic  operations 
characteristics  and  the  potential  impacts 
which  might  result  from  implementation.  The 
alternatives,  each  of  which  is  discussed 
below;  are  followed  by  a  brief  discussion 
of  the  feasibility  of  construction  of  a 
^northbound  tunnel  for  spl:..t:  alignment  con- 
figurations.  For  Alternatives  4-9,  it  has 
been  assumea  for  technical  analysis  pur- 
poses only,  that  the  split  alignment  with 
a  new  northbound  tunnel  will  have  three 
lanes  with  a  shoulder  used  in  peak  periods  to 
accommodate  traffic  demand.   Modifications 
will  be  made  to  the  existing  Dewey  Square 
Tunnel  to  allow  for  the  same  configuration. 


83 


%^. 


"=5^^. 


Existing  Expressways  c=ac3«=»== 
Existing  and  New  Transitways 
New  South  Area  Roadways 
Related  Roadway  Projects 


i 


ALTERNATIVE  i:  NO  BUILD 


Figure  24 


J4 


III. C. 3. a   Alternative  1  -  The  No  Build  Alternative 

The  No  Build  Alternative  has  been 
developed  to  explore  the  possibility  of 
retaining  the  existing  facility,  with 
some  modifications,  in  order  to  maximize  its 
economic  life.   The  viaduct  in  the  South 
Area  needs  replacement  of  the  decks  within  the 
immediate  future  if  no  other  improvements 
are  made.   Within  the  past  few  years  the 
Department  has  undertaken  stop-gap 
maintenance  measures   to  repair  certain 
sections  of  these  decks.   Unlike  the  central 
section  of  the  Artery,  these  decks  were 
designed  and  constructed  without  protective 
bituminous  concrete  wearing  surface.   As  a 
resiilt,  the  age  of  the  decks  coupled  with 
increasing  wheel  loads  and  salting  action  dur- 
ing the  winter  months,  has.  contributed  to  the 
deteriorating  condition  of  the  decks.   One 
possible  method  of  undertaking  this  work  is 
as  follows: 

Rebuilding  of  one  lane  of  the  decks  at 
a  time.   This  method  is  a  standard 
technique  when  traffic  must  be  maintained. 
It  has  the  obvious  disadvantage  of 
reducing  capacity  on  a  roadway  and  in  this 
case  reducing  it  by  at  least  one-third. 
However,  during  orevious   maintenance 
operations ,  replacement  capacity  was. 
found  on  the  parallel  frontage  roads 
along  both  sides  of  the  viaduct,  i.e., 
Albany  Street  on  the  western  side  and 
Frontage  Road  on  the  eastern  side.  If 
full  reconstruction  of  the  viaduct  were 
undertaken,  these  parallel  roadways 
could  be  used  during  the  construction 
period  to  act  as  a  queue  bypass . 

Selective  widening  of  the  Dewey  Square  Tunnel 
for  the  purposes  of  providing  speed  change  lanes 
or  breakdown  bays  in  key  locations  can   also  be 
undertaken  as  part  of  the  no-build  alternative. 
Subsequent  analysis  of  these  possibilities 
will  indicate  how  useful  they  might  be  in  im- 
proving safety  and  operations  of  the  tunnel. 
No-build  improvements  do  not  offer  a  long-term 
solution  to  the  problems  of  the  South  Area. 
Congestion,  delay  and  accidents  can  be  expected 
to  continue  at  the  present  level  and  to  worsen 
over  time.   Contiguous  land  areas  will  still 
be  subjected  to  traffic  spillover  with  its 
associated  environmental  problems. 


85 


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LEGEND • 


Existing  Expressways  = 
Existing  and  New  Trans 
New  South  Area  Roadway 
Related  Roadway  Projec 


1 


ALTERNATIVE  2:  NO  BUILD 

WITH  SPECIAL   PURPOSE  HARBOR  TUNNEL 


Figure   25 


III.C.3.b    Alternative  2  -  The  No  Build  Alternative 

with  a  Special-Purpose 
Third  Harbor  Tunnel 


Alternative  2  is  similar  to  Alternative 
1  in  all  respects,  except  for  a  special 
purpose  third  harbor  tunnel.  The 
connection  between  the  South  Area 
expressway  facilities  and  the  proposed 
tunnel  would  be  made  at  the  interchange 
between  the  Central  Artery  and  the 
Turnpike.   The  two-way  special  purpose 
tunnel  would  be  located  by  itself  in 
the  Fort  Point  Channel. 


This  alternative  has  no  South  Area  Artery 
improvements ,  and  would  have  serious 
disadvantages  for  the  overall  improvement 
of  the  Artery  and  upgrading  its  safety 
and  efficiency.   It  would  foreclose  any 
major  future  improvements  to  the  South 
Area  of  the  Artery  and  continue  the 
existing  substandard  operational  and 
safety  conditions  in  the  Dewey  Square 
Tunnel.   While  it  would  provide  improved 
service  to  limited  types  of  vehicles,  it 
would  primarily  serve  only  those  vehicles 
approaching  from  the  West  and  South. 
From  other  directions  such  vehicles 
would  have  to  travel  the  full  length  of 
the  Artery  to  reach  the  tunnel  approaches. 
It  would  have  the  salutory  effect  of 
removing  vehicles  from  the  Central  Area 
of  the  corridor,  to  the  extent  that  the 
service  provided  by  buses  or  other 
multiple-occupancy  vehicles  could  attract 
more  ridership. 


87 


SIJOD 


41 


Existing  Expressways  ■=>=5=== 
Existing  and  New  Trans itways 
New  South  Area  Roadways 
Related  Roadway  Projects 


ALTERNATIVE  3:  NO  BUILD 

WITH  GENERAL  PURPOSE  HARBOR  TUNNEL 


Figure  26 


III.C.3.C    Alternative  3  -  The  No  Build  Alternative 

with  a  General-Purpose 
Third  Harbor  Tunnel 


This  alternative  is  similar  to  Alternative 
1  in  all  respects,  except  for  a  general 
purpose  third  harbor  tunnel.   The  connection 
between  the  South  Area  expressway  facilities 
and  the  proposed  tunnel  would  be  made  at  the 
interchange  between  the  Central  Artery  and 
the  Turnpike.   The  two-way  general  purpose 
tunnel  would  be  located  by  itself  in  the 
Fort  Point  Channel.   There  would  be  no  changes 
in  the  existing  Dewey  Square  Tunnel,  because 
the  new  tunnel  would  operate  independently 
of  the  Artery  and  connecting  roadways. 

This  alternative  has  no  South  Area  Artery 
improvements,  and  would  have  serious  disadvan- 
tages for  the  overall  improvement  of  the  Artery 
and  upgrading  its  safety  and  efficiency.   It 
would  foreclose  any  major  future  improvements 
to  the  South  Area  of  the  Artery  and  continue  the 
existing  substandard  operational  and  safety 
conditions  in  the  Dewey  Square  Tunnel.   While 
it  would  provide  improved  service  to  the  Airport, 
it  would  primarily  serve  only  those  vehicles 
approaching  from  the  West  and  South.   From 
other  directions  such  vehicles  would  have  to 
travel  the  full  length  of  the  Artery  to  reach 
the  new  tunnel.   The  physical  connections  of 
the  new  tunnel  to  the  Artery  at  the  existing 
interchange  near  Kneeland  Street  is  more  complica- 
ted than  other  alternatives.   By  providing  for 
two-way  traffic  between  all  expressways  (and 
potentially  to  South  Station  as  well)  the  ramps 
in  the  interchange  must  be  substantially  revised 
both  in  alignment  and  profile  to  meet  the  new 
tunnel . 


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LEGEND • 


Existing  Expressways  «= 
Existing  and  New  Transitways 
New  South  Area  Roadways 
Related  Roadway  Projects 


1 


ALTERNATIVE  4:  SPLIT   ALIGNMENT 

WITH  NO  OTHER  MAJOR  IMPROVEMENTS 


Figure   2'7 


90 


III.C.3.d  Alternative  4  -  Split  Alignment  with 

no  other  major  improve- 
ments 

In  this  alternative,  the  South  Area  of 
the  Artery  is  reconstructed  but  no  major 
improvements  are  made  to  the  central  sec- 
tion.  The  reconstruction  of  the  South  Area 
would  include  splitting  the  alignments, 
with  the  new  1-93  northbound  tunnel  located 
in  the  Fort  Point  Channel  or  under  Atlantic 
Avenue.   It  would  be  connected  to  the  elev- 
ated central  Section  in  the  vicinity  of  Nor- 
thern Avenue.   The  Dewey  Square  Tunnel  would 
be  retained  for  southbound  movement,  with 
modification  of  the  existing  tunnel  and  ramps 
to  accomodate  the  split  of  north-&  southbound 
movement.   At  least  3  lanes  with  a  shoulder  used 
in  peak  periods  to  accommodate  traffic  demand 
will  be  provided  in  both  tunnels.   Local  street 
connections  would  be  modified  to  improve  service 
between  the  expressways  and  the  surface  streets. 
Additional  ramps  could  be  provided  at  a  later 
date  to  connect  to  the  third  harbor  tunnel^ 
if  that  facility  is  to  be  constructed. 

Additional  capacity  in  the  Dewey  Square 
Tunnel  would  provide  traffic  relief  for  the 
South  Area.   New  connections  to  the  local 
street  network-  would  improve  access  to  and 
from  the  South  Boston /seaport  areas.  South 
Station  and  the  proposed  transportation  ter- 
•  minal,  and  the  retail  and  financial  districts 
of  downtown  Boston.   Since  these  improvements 
connect  directly  with  the  Central  Area  of  the 
Artery,  the  Massachusetts  Turnpike,  and  the 
Southeast  Expressway,  each  of  the  facilities 
would  also  benefit  from  improved  traffic  ser- 
vice in  the  South  Area. 

This  alternative- is  not  contingent  upon  the 
Central  Area  Artery  improvements ,  and  thus 
would  require  a  distinctive  treatment  of 
the  link  between  the  northbound  tunnel  and 
the  existing  elevated  Artery  structure  near 
Northern  Avenue. 


91 


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LEGEND 


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2ri 


Existing  Expressways  «= 
Existing  and  New  Transitways 
New  South  Area  Roadways 
Related  Roadway  Projects 


ALTERNATIVE  5:  SPLIT  ALIGNMENT 

WITH   SPECIAL   PURPOSE  HARBOR  TUNNEL 


Figure  28 


92 


III.C.3.e   Alternative  5  -  Split  alignment 

without  the  Central  Area 
Project  and  with  a  Special 
Purpose  Third  Harbor  Tunnel 


This  alternative  is  similar  to  Alternative 
4  with  the  addition  of  the  special -purpose 
tunnel  to  and  from  the  airport.   Connection 
to  and  from  the  harbor  tunnel  would  be 
made  to  both  the  new  northbound  roadway 
and  the  existing  Dewey  Square  Tunnel. 

This  alternative  would  allow  construction 
of  the  northbound  roadway  and  the  special- 
purpose  tunnel  to  be  undertaken  without 
disruption  to  existing  traffic.   However, 
connections  between  the  new  north  - 
bound  tunnel    and  existing  roadways  could 
not  be  made  without  some  traffic  disruption 
during  the  construction  period. 


93 


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LEGEND 


Existing  Expressways  «=«=:== 
Existing  and  New  Trans itways 
New  South  Area  Roadways  vmm^ 
Related  Roadway  Projects  ■-• » 


ALTERNATIVES:  SPLIT  ALIGNMENT 

WITH  GENERAL  PURPOSE  HARBOR  TUNNEL 


* 


Figure  2  9 


94 


III.C.3.f   Alternative  6  -  Split  Alignment 

without  the  Central  Area 
Project  and  with  a  General- 
Purpose  Third  Harbor  Tunnel 


This  alternative  is  the  same  as 
Alternative  5  with  the  exception  of  general 
purpose  traffic  utilizing  the  proposed  har- 
bor tunnel . 


J?/ 


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LEGEND 


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I 


Existing  Expressways  ■= 
Existing  and  New  Transitways 
New  South  Area  Roadways  i 
Related  Roadway  Projects 


ALTERNATIVE  7:  SPLIT   ALIGNMENT 

WITH  CENTRAL  AREA  RECONSTRUCTION 


Figure   30 


96 


^^^'C.3.'^      Alternative  7  -  Split  Alignment  with 

the  Central  Area  Project 

As  in  Alternatives  4-6,  this  alternative 
provides  for  a  major  improvement  in  the 
South  Area  with  the  construction  of  a  new 
northbound  roadway  parallel  to  the  Dewey 
Square  Tunnel.   The  existing  Dewey  Square 
Tunnel  would  then  become  one-way  south- 
bound.  Both  the  relocated  northbound  road- 
way and  the  improved  southbound  roadway 
would  link  to  a  rebuilt  Central  Area  of 
the  Artery.   The  connection,  located  near 
the  Northern  Avenue  Bridge,  would  be  under- 
ground.  Additional  connections  could  be 
provided  at  a  later  date  to  the  proposed 
third  harbor  tunnel  if  that  facility  is 
to  be  constructed. 

While  no  definitive  construction  staging 
has  yet  been  developed,  it  is  anticipated 
that  the  sequencing  might  proceed  by  first 
constructing  the  new  northbound  roadway 
tunnel.   Northbound  traffic  could  then  be 
shifted  from  the  existing  roadway  to  the 
new  tunnel  alignment.   Southbound  traffic,  ■ 
north  of  the  Dewey  Square  Tunnel,  could  be 
shifted  to  the  northbound  roadway  in  the 
tunnel  while  modifications  are  made  to 
southbound  tunnel  tube  and  connections 
made  to  the  central  section.   The  time  to 
complete  this  work  is  estimated  to  be  three 
years,  depending  on  the  linkage  to  the 
central  section  of  the  Artery. 

The  proposed  North  Station-South  Station 
rail  connection,  which  is  part  of  the 
Central  Area  project,  is  not  a- part  of 
any  alternative  for  the  South  Area,  except 
immediately  behind  South  Station.   At  that 
location,  any  future  direct  access  roads 
into  the  proposed  South  Station  Transpor- 
tation Terminal  would  have  to  cross  the 
alignment  of  the  proposed  underground 
rail  connection. 


Existing  Expressways  c=3e=3c=t= 
Existing  and  New  Transitways 
New  South  Area  Roadways 
Related  Roadway  Projects 


98 


1- 

ALTERNATIVE  8:  SPLIT  ALIGNMENT 

WITH  SPECIAL  PURPOSE  HARBOR   TUNNEL  AND  CENTRAL  AREA  RECONSTRUCTION 

Figure  31 


^^^■^■^•h      Alternative  8  -  Split  Alignment  with  the 

Central  Area  Project  and 
a~ Special  Purpose  Third 
Harbor  Tunnel 


Alternative  8  is  similar  to  Alternative  7 
and  includes  a  special-purpose  third  harbor 
tannel  to  and  from  the  airport.   The  tunnel 
would  connect  with  the  South  Area  project 
in  the  vicinity  of  Northern  Avenue,,  and 
would  link  to  the  new  northbound  roadway  and  " 
the  existing  Dewey  Square  Tunnel.   Local 
street  connections  would  be  provided  as  in 
Alternative  7. 

As  in  Alternative  7,  construction  of  the 
northbound  roadway  and  the  special-purpose 
tunnel  could  be  undertaken  without  disruption 
to  existing  traffic.   Construction  phasing  of 
this  alternative  would  be  closely  integrated 
with  the  phasing  of  the  Central  Area  improve- 
ments . 


99 


Existing  Expressways  c=3e=3c=3«= 
Existing  and  New  Trans itways 
New  South  Area  Roadways  ■ 
Related  Roadway  Projects 


100 


ALTERNATIVE  9:  SPLIT  ALIGNMENT 

WITH  GENERAL  PURPOSE  HARBOR  TUNNEL  AND  CENTRAL  AREA  RECONSTRUCTION 

Figure  32  f 


Ill.C.S.i   Alternative  9  -  Split  Alignment  with  the 

'Central  Area  Project  and  a 
General  Purpose  Third  Harbor 
Tunnel 


Alternative  9  is  the  same  as  Alternative  8 
except  that  the  third  harbor  tunnel  is  a 
general-purpose  facility  to  and  from  the 
airport.   The  tunnel  would  connect  with  the 
South  Project  in  the  vicinity  of  Northern 
Avenue  and  lead  to  the  aJ.rport  access  road. 
Direct  connections  between  the  third  harbor 
tunnel  and  the  North  Shore  would  not  be 
provided  in  this  option.   There  would  be 
direct  connections  for  traffic  between  the 
Southeast  Expressway  and  the  Massachusetts 
Turnpike  and  the  harbor  tunnel.   Access  from 
the  north  and  northwest  to  the  harbor  tunnel 
would  be  less  direct;  this  traffic  would 
continue  to  use  the  present  harbor  tunnels 
for  access  to  and  from  the  airport. 


101 


III.C.4   Construction  Feasibility 


Preliminary  plans  for  the  South  Area 
include  several  alternatives  which  have 
been  investigated  in  some  detail  to  determine 
their  feasibility.   Those  alternatives  which 
rebuild  the  existing  facilities  have  ample 
and  substantial  precedents  for  feasibility. 
Replacing  of  decks  has  been  undertaken  on 
several  roadways  in  the  Commonwealth,  thus 
giving  precedent  on  technique  for  sequencing 
of  construction  and  undertaking  the  demoli- 
tion of  existing  decking  and  replacing  it 
with  new  surfaces. 

Those  alternatives  which  call  for  a  new  tun- 
nel in  the  Fort  Port  Channel  have  signifi- 
cant distinctions  from  previous  projects  to 
warrant  special  mention.   The  preliminary 
plans  call  for  a  siabaquaeous  tunnel  in  the 
Channel  to  carry  northbound  traffic.   Major 
problems  confronting  construction  of  this 
tunnel  include  the  proximity  of  the  South 
Postal  Annex,  the  Stone  and  Webster  Building, 
the  bulkhead  supporting  Dorchester  Avenue, 
the  Channel  bridges  at  Summer  and  Congress 
Streets  and  at  Northern  Avenue,  and  the  Red 
Line  MBTA  tunnels.   The  transit  tunnels  are 
located  in  mid-channel  and  are  parallel  to 
the  proposed  northbound  Artery  tunnel  for 
approximately  2800  feet  before  turning  to 
pass  inland  under  Suiraner  Street.   The 
transit  tunnels  were  built  over  50  years  ago 
and  are  very  sensitive  to  any  changes  in  the 
existing  balance  of  sub-surface  pressures. 
Subsurface  conditions  in  the  channel  indi- 
cate the  presence  of  soft  compressible  and 
unstable  soils  overlying  clay  and  glacial 
till.   The  design  of  the  Artery  tunnel  must 
safeguard  the  existing  Red  Line  tunnels 
against  imposition  of  either  vertical  or 
lateral  loads ,  both  during  and  after 
completion  of  construction. 

Preliminary  design  alternatives  have  been 
developed  for  the  Fort  Point  Channel  tunnel. 
They  include  a  sunken  tube,  cut-and-cover  and 
mined  tunnel  designs.   If  built  within  the 
Channel  (as  opposed  to  under  the  right-of-way 
of  Dorchester  Avenue)  the  most  appropriate 
design  may  be  a  sunken  tube.   However,  the 
problems  of  constructing  the  tunnel  so 
close  to  the  Red  Line  tubes  may  dictate 
construction  of  the  tunnel  within  the  confines 
of  a  diaphragm  sheet  pile  cofferdam,  or 


102 


concrete  slurry  wall  consisting  of  continuous 
bored,  cast-in-place  concrete  piles. 

If  construction  of  sunken  tube  technique  is  to 
be  utilized,  the  tunnel  sections  are  constructed 
off-site  and  floated  into  place  as  needed. 
Preparation  work  for  the  floor  to  support 
the  tubes  is,  however,  complicated  by  the 
presence  of  the  Red  Line  tunnels.   One  method 
which  has  been  investigated  is  the  preparation 
of  the  site  for  each  section  of  tube  by 
installation  of  a  series  of  underground  pile 
bents.   This  work  is  succeeded  by  the 
construction  of  a  cofferdam,  which  allows 
dewatering  of  the  site,  and  construction  of 
concrete  pile  caps  to  sustain  the  tubes.   When 
completed,  one  end  of  the  cofferdam  is 
removed  and  the  prefabricated  tubes  are 
floated  into  place  and  installed.   The 
entire  cofferdam  is  then  removed  and 
surfaces  are  then  prepared  for  landscaping 
or  other  uses. 

Alternatively,  it  is  also  feasible  to 
construct  the  tunnel  within  the  confines  of 
a  continuous  diaphragm  wall  to  serve  as  a 
cofferdam.   By  making  the  cofferdam 
wide  enough  to  accomodate  the  width  of 
proposed  construction,  it  would  provide  a 
construction  area  within  which  a  concrete 
structure  could  be  constructed  in  the  dry. 
When  completed,  the  construction  cofferdam 
wall  may  be  retained  to  serve  as  a  permanent 
structural  wall.   At  the  location  where  the 
tunnel  must  cross  the  Red  Line  tunnel  (as  it 
turns  to  go  under  Summer  Street) ,  pres tressed- 
precast  tunnel  sections  would  bridge  the 
area  without  imposing  any  load  on  the  Red 
Line  tunnels.   The  foundation  support  for 
this  bridge  type  section  could  consist  of 
either  bearing  directly  on  the  granular 
soils  as  a  spread  footing,  or  of  pile 
or  caissons  founded  in  glacial  till. 

Construction  inland  from  the  Fort  Point 
Channel  is  basea  on  more  conventional 
techniques.  The  option  of  a  new  northbound 
tunnel  under  Atlantic  Avenue  would  be  con- 
structed in  that  vicinity  by  the  cut  and 
cover  technique.   Direct  connections  to 
Northbound  tunnel  would  require  a 
driven  tunnel  to  pass  under  the  South 
Station  rail  yards.   Alternatives  which  in- 
clude a  tunnel  connection  with  the  Central 
section  of  the  Artery  would  be  in  soft  ground 
clay  or  glacial  till,  but  would  have  to  include 


103 


consideration  of  old  foundations, 
piles,  and  other  fill  which  lies 
underground.   Alternatives  which 
connect  the  proposed  Fort  Point 
Channel  tunnel  with  the  existing 
elevated  Artery  structure  would  be 
part  below,  part  above  grade  in  the 
vicinity  of  Northern  Avenue.   In  all 
cases,  construction  staging  would  have 
to  be  devised  to  permit  continuous 
operation  of  existing  rail  and  road 
operations  in  the  South  Area. 

Artificial  ventilation  of  road 
tunnels  is  required  where  the  noxious 
and  toxic  gases  and  smoke  emitted 
from  the  exhausts  of  vehicles  become 
either  a  danger  or  a  nuisance.   The 
principal  hazard  is  carbon  monoxide, 
and  the  principal  nuisance  is 
reduced  visibility  caused  by  smoke 
and  moisture.   The  concentration  of 
these  and  other  contaminants  tends  to 
vary  with  the  tunnel  cross-section, 
grade  and  length;  the  nximber,  size, 
speed,  load  and  engine  type  of  the 
various  vehicles  using  the  tunnel ;_ 
the  kind  of "ventilation  provided; 
the  source  and  quality  of  the 
fresh  air  entering-  the  tunnel  either 
by  natural  or  mechanical  means;  and 
altitude  and  wind  conditions.   The 
tunnel  designer  is  limited  to 
control  of  cross  section,  grade 
and  ventilation,  and  these  have  to 
be  combined  to  produce  acceptable 
results  under  the  worst  conditions. 

Design  considerations  must  also  be 
given  to  the  effect  of  tunnel 
exhaust  on  surface  conditions  above. 
Contaminants  are  no.  more  acceptable 
outside  than  inside  the  tunnel,  so 
dispersion  of  the  fumes  is  essential. 
Traffic  noise,  fan  noise  and  air  noise 
must  be  absorbed  or  attenuated;  and  the 
location  and  velocity  of  intake  and 
discharge  must  be  carefiilly  established. 
The  number,  location,  area,  height  and 
appearance  of  intake  and  discharge 
structures  must  not  create  audible, 
visible  or  smellable  nuisances*   They  can 
in  the  alternatives  for  the  South  Area, 
avoid  the  taking  of  private  property. 


104 


III.D     ASSESS^IENT  OF  IMPACTS 

This  discussion  summarizes  findings  of  anal- 
yses of  nine  alternatives  for  the  South  Area 
of  the  Central  Artery  corridor.   It  is  based 
upon  past  studies  and  analyses  of  current 
proposals  for  South  Area  improvements ,  the 
detailing  of  transportation  impacts  of  the 
current  proposals,  and  the  social,  economic 
and  environmental  consequence  of  alternative 
improvements.   The  following  sections 
include  a  summary  of  findings  resulting  from 
the  analysis — presented  in  the  form  of  two 
charts,  with  explanations  in  the  text  which 
follows  (see  Figures  33  ana  34).  For 
purposes  of  analysis,  it  has  been  assumed  • 
that  the  Fort  Point  Channel  tunnel  in 
Alternatives  4-9  will  consist  of  three 
northbound  lanes,  with  a  shoulder  used  in 
peak  periods  to  accomodate  traffic  demand. 


III.D. 1 


Transportation  Operational  Improvements 

Length  of  Queues 

Queues  in  the  South  Area  of  the  Artery  Corridor 
are  associated  with  access  into  it  from  the 
south  and  with  the  capacity  of  the  Dewey 
Square  Tunnel.   Principal  queue  areas  are 
foxond  on  the  Southeast  Expressway  and  Mass. 
Turnpike  entrances  to  the  Artery.   Because 
of  the  limited  capacity  within  the  Dewey 
Square  Tunnel,  the  effect  is  a  metering  of 
traffic  between  the  queues  and  the  Tunnel. 

P.emoval  of  the  queues  through  each  of  the 
no-build  alternatives  (1,2,  and  3)  is  not 
possible;  they  can  only  be  mitigated  in  minor 
ways,  unless  a  major  widening  of  the  Dewey 
Square  Tunnel  is  undertaken. 

Queuing  on  the  proposed  split  alignment 
alternatives  (4  through  9)  will  be  less 
because  the  capacity  of  the  proposed  facilities 
will  be  increased,  and  additional  surface 
street  options  and  connections  will  be  made 
available  within  the  South  Area.   For  example, 
the  proposed  northbound  ramp  to  Northern 
Avenue  and  ramps  to  and  from  Atlantic  Avenue 
will  assist  in  distributing  traffic  which  now 
must  pass  through  the  queue  at  the  mouth  of  the 
Dewey  Square  Tunnel. 


105 


Metering  of  traffic  from  the  South  Area  of 
the  Corridor  into  the  Central  Area  will  be  . 
partially  retained  in  Alternatives  4,5  and  6 
which  do  not  include  reconstruction  of  the 
Central  Area.   In  those  instanc^-a,  it  may 
be  essential  to  seek  alternative  means  for 
distribution  of  traffic  which  minimizes  the 
use  of  the  Central  Area  for  local  downtown 
access.   This  would  retain  the  capacity  of 
the  central  portion  of  the  Artery  for  through 
movements  or  for  longer  distribution  trips 
within  downtown.   The  reverse  direction  from 
the  Central  Area  into  the  South  Area  of  , 
the  corridor  should  not  result  in  difficulties 
in  queueing,  because  the  capacity  of  the 
South  Area  in  Alternatives  4,5  and  6  will  be 
somewhat  greater  than  that  of  the  Central 
Area. 

Annual  Delay  Reduction  (hours  in  peak  periods) 
Delay  reductions  on  the  Artery  are  expressed 
in  the  following  list.   (Note  that  this  does 
not  include  delay  reduction  on  either  connect- 
ing expressway  facilities  or  on  local  surface 
streets.)   Average  vehicle  speeds  in  peak 
periods  are  also  shown  for  each  alternative. 

Annual  Delay  Reduction  (hours  in  peak  periods) 

Alternative  1  -  None  at  opening,  delay  to 

increase  over  time  as  con- 
gestion builds 

Alternative  2  -■    53,600  hours 

Alternative  3  -    114,000  hours 

Alternative  4  -    408,000  hours 

Alternative  5  -    742,000  hours 

Alternative  6  -    847,000  hours 

Alternative  7  -  1,061,000  hours 

Alternative  8  -  1,121,000  hours 

Alternative  9  -  1,156,000  hours 

Average  Vehicle  Speed  in  Peak  Period 


Alternative 

1  - 

-  19 

moh 

Alternative 

2  - 

-  20 

mph 

Alternative 

3  - 

-  21 

mph 

Alternative 

4  - 

-  27 

mph 

Alternative 

5  - 

-  28 

mph 

Alternative 

6  - 

-  28 

mph 

Alternative 

7  - 

-  40 

mph 

Alternative 

8  - 

-  40 

mph 

Alternative 

9  - 

-  40 

mph 

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IMPACTS 


Length    of    AM    queue 
northbound     (miles) 

1 . 80    miles 

I.JO    miles 

1.50    miles 

0.70    miles 

0.40  miles 

0.35  miles 

minimal 

minimal 

minimal 

Annual    delay 
reduction     (hrs    in 
peak    periods) 

none;     delay    to 
increase    over 
time 

53,600 

114,000 

408 , 000 

742 ,000 

847,000 

1,  061 ,000 

1,121,300 

1,156,000 

Average    vehicle 
speeds     (in    peak 
periods ) 

19    mph 

2  0    mph 

21   mph 

27    mph 

2  8   mph 

28   mph 

40    mph 

40   mph 

40    "Ph 

Annual    value    of 
time    saved    -    auto 
driver    and    passr 

none;     travel 
time    penalties 
over    time 

$494,500 

$908,000 

$1,986,000 

$2,166,000 

$2,306,000 

$2,667,000 

$2,759,000 

$2,896,000 

Annual    value    of 
time    saved    -    bus 
pas  senger 

none;     travel 
time    penalties 
over    time 

S    89,400 

$164,000 

$       614,200 

$     890,000 

$1,016,000 

$1,273,000 

$1,505,600 

$1,608,400 

Annual    value    of 
vehicle    hours 
saved    -    buses 

none;     travel 
time    penalties 
over    time 

S       5,200 

S       9,500 

S       35,700 

S        51,700 

$          59,300 

$          74,000 

$          87,500 

$          93,400 

Annual    value    of 
veh .     hrs    saved    - 
commercial    veh. 

none;     travel 
time    penalties 
over    time 

S       6,500 

$    15,200 

$       31,700 

$         66,900 

$       147,900 

$       152,700 

$       153,900 

$        155,900 

Annual    operating 
savings    -    all 
vehicles 

none ; increased 
costs    over 

time 

$       8,600 

$     24,000 

$    83,500 

$           92,100 

$        107,500 

S        142,400 

$       146,800 

$        152,300 

Annual    number 
of    accidents 

450 

430 

405 

181 

149 

143 

115 

105 

105 

Annual    accident 
reduction    - 
percent 

none 

-5% 

-10% 

-60% 

-67% 

-68% 

-74% 

-77% 

-77% 

Annual    accident 
reduction    - 
dollar    savings 

none 

$     50,800 

$101,600 

,        990,000 

5    1,105,200 

$1,122,100 

$    1,220,000 

$1,270,200 

$1,270,200 

Interstate 
standards 

no 

no 

no 

improved 

improved 

improved 

,    .  - 

improved 

improved 

improved 

Note:  For  purposes  of  analysis.  No  Build  Alternatives 

do  not  include  major  alterations  to  existing  structures 


Figure  33   Summary  of  Anticipated  Transportation  Impacts 


IMPACTS 


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Direct  tax  base 
impacts 

no  change 

no  change 

no  change 

slight 
positive 

slight 
positive 

slight 
positive 

positive 

positive 

positive 

Net  new  acres 
for  development 

none 

none 

none 

1.9  acres 

1.9  acres 

1.9  acres 

5.6  acres 

5.6  acres 

5.6  acres 

Dollar  value  of  land 
for  new  development 

none 

none 

none 

$2,574,000 

to 

$4,980,000 

$2,674,000 

to 

$4,980,000 

$2,674,000 

to 

$4,980,000 

$7,924,000 

to 

$15,726,000 

$7,924,000 

to 

$15,726,000 

$7,924,000 

to 

$15,726,000 

Impact  on  community 
quality  and  character 

no  change 

no  change 

no  change 

slight 
positive 

slight 
positive 

slight 
positive 

slight 
positive 

slight 
positive 

slight 
positiive 

Air  quality  impacts 
Tons/year 

CO:   4990 
HC:    620 
NOy:    760 

CO:   4970 
HC:    620 
NOx:    780 

CO:   5070 
HC:    630 
NOx:    770 

CO:   3720 
HC:    540 
NOx:   990 

CO:   3010 
HC:     490 
NOx:  1010 

CO:   3020 
HC:    490 
NOx:  1030 

CO:   3140 
HC:    530 
NOx:  1270 

CO:   3000 
HC:    510 
NOx:  1210 

CO:   3000 
HC:     500 
NOx:  1210 

Hoise  impacts 

no  change 

no  significant 
increase  or 
decrease 

no  significant 
increase  or 
decrease 

no  significant 
increase  or 
decrease 

no  significant 
increase  or 
decrease 

no  significant 
increase  or 
decrease 

slight  improve- 
nent  north  of 
Dewey  Sq  Tunnel 

slight  improve- 
ment north  of 
Dewey  Sq  Tunnel 

slight  improve 
ment  north  of 
Dewey  Sq  Tunne 

Water  quality  impacts 

no  change 

no  change 

no  change 

improvement 
in  Fort  Point 
Channel 

improvement 
in  Fort  Point 
Channel 

improvement 
in  Fort  Point 
Channel 

Improvement  in 
F'ort  Point 
Channel 

improvement  in 
Fort  Point 
Channel 

improvement  in 
Fort  point 
Channel 

Overall  impact  - 
Dewey  Sq. Tunnel  area 

negative 

negative 

negative 

positive 

positive 

positive 

major 
positive 

major 
positive 

major 
positive 

Overall  impact  - 
South  of  Dewey  Sq. 
Tunnel 

negative 

negative 

negative 

positive 

positive 

positive 

positive 

positive 

positive 

Project  life 

30  yrs-decks 

30  yrs-decks 

30  yrs-decks 

40  yrs-tunnel 
30  yrs-decks 

40  yrs-tunnel 
30  yrs-decks 

40  yrs-tunnel 
30  yrs-decks 

40  yrs-tunnel 
30  yrs-decks 

40  yrs-tunnel 
30  yrs-decks 

40  yrs-tunnel 
30  yrs-decks 

Construction  Costs  - 
South  Area  Artery 
proiect  (000) 

$10,640 

$10,640 

$10,640 

$190,580 

$190,580 

$190,580 

$190,580 

$190,580 

$190,580 

Construction  Costs  - 
Related  projects 
(000) 

none 

$409,940 

$634,420 

none 

$312,760 

$390,720 

$875,000 

$1,187,761 

$1,265,720 

Construction 
duration 

one  year 

1  year  plus 
4  years  for 
tunnel 

1  year  plus 
5  years  for 
tunnel 

three  years 

3  years  plus 

4  years  for 
tunnel 

3  years  plus 
5  years  for 
tunnel 

three  years 

3  years  plus 

4  years  for 
tunnel 

3  years  plus 
5  years  for 
tunnel 

Types  of  construction 
disruption 

Moderate 
to  severe 

Moderate 
to  severe 

Moderate 
to  severe 

Minimum  to 
Moderate 

Minimum  to 
Moderate 

Minimum  to 
Moderate 

Minimum  to 
Moderate 

Minimum  to 
Moderate 

Minimum  to 
Moderate 

Note:  For  purposes  of  analysis.  No  Build  Alternatives 

do  not  include  major  alterations  to  existing  structures 


Figure  34  :  Summary  of  Environmental  fi  Community  Impacts 


I 


Annual  Value  of  Time  Saved  in  Peak  Periods 
Figure  33  illustrates  the  benefits  of  time 
savings  to  varying  road  users,  projected 
as  a  result  of  implementing  each  of  the 
alternatives.   These  figures  are  expressed 
for  the  year  in  which  each  alternative 
would  be  open  and  used;  values  are  ex- 
pressed in  19  75  dollars  for  comparative' 
purposes.   Each  alternative  also  reflects 
highway  system  analyses  which  include 
induced,  new  and  diverted  trips  resulting 
from  implementation  of  the  proposed  improve- 
ments. 

A  conservative  approach  has  been  adopted  in 
presenting  the  anticipated  benefits;  that 
is.  benefits  are  shown  only  for  peak  hours 

(7:00  -  9:00  a.m.  and  4:00  -  6:00  p.m.) 
and  only  for  users  of  the  South   Area  of 
the  Artery  Corridor.   Benefits  from  the 
implementation  of  proposed  improvements  in 
other  portions  of  the  Artery  Corridor  are 
not  included  in  the  chart.   The  chart  thus 
gives  a  modest  picture  of  anticipated  bene- 
fits, however   the  analysis  has  been  expanded 
below  for  comparative  purposes. 


In  addition  to  the  value  of  time  savings 
shown  in  Figure  33  for  auto  drivers  and 
passengers,  bus  passengers,  commercial 
vehicles  and  buses,  the  following  chart 
shows  total  savings  accruing  to  all  users 
for  each  alternative. 

Annual  Value  of  Time  Saved  for  All  Users 

Alternative  1  -  None 
Alternative  2  -  $  595,600 
Alternative  3  -  $1,096,700 
Alternative  4  -  $2,667,600 
Alternative  5  -  $3,174,600 
Alternative  6  -  $3,529,200 
Alternative  7  -  $4,166,700 
Alternative  8  -  $4,506,000 
Alternative  9  -  $4,753,700 

Annual  Operating  Savings  in  Peak  Periods  - 
All  Vehicles 

Costs  of  operating  vehicles  are  major  for 
all  users,' and  especially  so  in  peak  periods 
when  delays  and  queueing  most  often  occur. 


1  1  T 


III.D.2 


The  following  chart  shows  the  operational 
savings  for  all  vehicles  which  result  in 
peak  periods  following  implementation  of 
each  of  the  alternatives.   These  benefits 
are  expresses  for  the  year  in  which  each 
alternative  would  be  open  for  use;  they  are 
shown  in  1975  dollars  for  comparison. 

Alternative  1  -  none 

Alternative  2  -  $  8,600 

Alternative  3  -  $  24,000 

Alternative  4  -  $  83,50  0 

Alternative  5-  $92,100 

Alternative  6  -  $107,500 

Alternative  7-  $142,400 

Alternative  8  -  $146,800 

Alternative  9  -  $152,000 


Safety 

Accident  Reduction 

The  table  below  reflets  estimated  annual 
accidents  for  each  of  the  alternatives, 
including  the  percent  of  reduction  from  the 
base  case  (Alternative  1)  and  the  dollar 
value  which  is  assignable  to  the  accident 
reduction  for  each. 

Alternative  Annual  No.    Percent    Dollar 
Accidents Reduction   Savings 

1  450 

2  430 

3  405 

4  181 

5  149 

6  143 

7  115 

8  105 

9  105 

Interstate  Standards 

Alternatives  1,  2  and  3  do  not  meet  interstate 
standards.   Improvements  will  not  change  Artery 
conditions  relative  to  these  standards.   Alter-- 
natives  4  through  9  will  improve  roadway  confi- 
guration and  performance,  bringing  the  Artery 
close  to  conformance  with  the  standards. 


0% 

5% 
10% 

none 

$   50,800 

3   101,600 

60% 

$   990,000 

67% 

$1,105,200 

68% 

$1,122,100 

74% 

$1,220,000 

77% 

$1,270,200 

77% 

$1,270,200 

112 


III.D. 3 


Regional  and  Ccminunity  Impacts 

The  Artery  affects  the  economic  vitality  of  all 
of  Downtown  Boston,  which  is  not  only  the  core  of 
the  metropolitan  area,  but  the  economic  and  cul- 
tural focus  of  the  New  England  Region.   The  pro- 
posed improvement  alternatives  affect  both  the 
local  community  and  the  metropolitan  and  New  Eng- 
land Regions  in  different  ways. 

Alternatives  1,  2  and  3  provide  no  opportunities 
to  enhance  the  growth  and  development  of  Downtown 
Boston.   Even  if  operational  improvements  were 
made,  the  negative  effects  of  the  present  facility 
would  remain.   Traffic  would  continue  to  spill 
onto  local  streets  to  avoid  the  Artery,  and  the 
negative  impacts  of  the  Artery  on  adjacent  land 
parcels  would  continue  to  constrain  development 
possibilities.   The  improvements  of  Alternatives 
1,  2  and  3  not  only  continue  the  negative  impacts 
of  the  Artery,  but  prolong  the  period  of  these 
impacts  of  the  present  facility  into  the  long- 
range  future. 

Alternatives  4  through  9,  on  the  other  hand, 
afford  the  possibility  of  implementing  a  long- 
range  strategy  for  the  improvement  of  the  economic 
future  of  the  Downtown  area.   The  removal  of  the 
constraint  posed  by  the  Artery  will  enhance  devel- 
opment possibilities  on  lands  which  are  adjacent  t 
the  Artery.   In  addition,  new  opportunities  arise 
for  development  on  the  decks  over  the  tunneled 
Artery.   In  transportation  terms,  the  impacts 
caused  presently  by  spillover  of  traffic  onto 
local  streets  will  be  reduced.   Improved 
accessibility  resulting  from  the  rebuilt 
Artery  will  enhance  properties  within  and  ad- 
jacent to  the  Artery  Corridor.   Since  much 
of  this  property  is  in  the  heart  of  the  metro- 
politan area,  this  is  a  major  benefit  for 
the  implementation  of  state  and  federal  policy 
aimed  at  the  restoration  and  enhancement  of 
older  urban  centers.   Improvements  made  throug  . 
Alternatives  4  through  9  will  last  only  for  the 
immediate  future,  but  also  for  the  very  long- 
term  future  of  Downtown  Boston. 

Tax  Base  and  Development  Impacts 
Alternatives  1,  2  and  3   would  have  no 
impacts  on  the  tax  base  nor  would  they  provde 
new  acreage  for  development.   Alternatives  4 
through  9  have  tax  base  impacts  in  both  the 
taking  of  properties  and  the  reinstitution 
of  new  uses  made  possible  through  the  highway 


113 


improvements.   Tax  losses  would  be  incurred 
if  the  Sheraton  Building  were  to  be  taken 
along  with  other  commercial  buildings  in  the 
vicinity  of  Northern  Avenue.  These  losses 
could  be  offset  with  the  possible  positive  tax 
advantages  resulting  from  the  development  of 
new  buildings  on  parcels  created  within  the 
highway  right-of-way,  above  the  new  tunnels. 
Alternatively,  if  the  tunnel  is  constructed 
between  the  Fort  Point  Channel  and  a  recon- 
structed Central  Area  of  the  corridor,  several 
of  the  buildings,  such  as  the  Shercitcn  Building, 
could  be  saved  through  underpinning  for  tunnel 
construction. 

Impact  on  Community  Quality  and  Character 
This  is  an  overall  impact  evaluation  of 
factors  which  are  difficult  to  quantify  but 
which  reflect  comirunity  and  envircnirental 
concerns.   These  include  visual  and  aesthetic 
qualities,  pedestrian  amenities  and  the  local 
street  pattern  and  its  relation  to  the  express- 
way network. 

Alternatives   No  change  in  community  quality 
1,2,  and  3     or  character  over  the  present 

situation.   The  present  negative 
influence  of  the  transportation 
facilities  in  the  area  will 
continue - 

Alternatives    In  the  vicinity  of  Northern 
4,  5  and  6     Avenue,  these  alternatives 

may  continue  some  of  the  present 
impacts  of  traffic  extending 
from  the  Dewey  Square  Tunnel  to 
the  elevated  viaduct  in  the 
Central  Portion  of  the  Corridor. 
Ramps  from  the  northbound  tunnel  in  either  the 
Atlantic  Avenue  or  the  Fort  Point  Channel 
alignment  would  extend  from  underground  to  the 
existing  Artery  via  a  long  ramp.   This  ramp 
would  pass  over  Northern  Avenue  and  j-oin  the 
elevated  highway  near  Harbor  Towers.   The 
ramp  would  be  carefully  designed  to  avoid 
potential  negative  impacts  on  adjacent  land 
uses. 

Between  Northern  Avenue  and  the  Kneeland  Street 
area,  both  split  alignment  alternatives  are 
in  tunnel  and  would  have  community  impacts 
only  in  the  vicinity  of  entrance  and  exit 
ramps.   The  precise  location  of  these  ramps 
would  be  determined  through  more  detailed 
study.   South  of  Kneeland  Street  and  extending 


114 


to  a  point  south  of  the  Massachusetts  Avenue 
interchange,  all  alternatives  are  identical 
in  terms  of  potential  community  impacts.   The 
existing  alignment  of  the  Artfery  would  be 
retained  with  modifications  to  surface  frontage 
•roads  and  some  potential  widening  of  the 
expressway  to  allow  for  construction  staging 
or  safety  and  capacity  improvements.   This 
widening,  if  carried  forward,  woudl  be 
carefully  considered  to  avoid  impacts  on  the 
community  and  to  adjust  ramp  connections  to 
fit  closely  with  desired  surface  street 
patterns. 

Alternatives   In  the  vicinity  of  Northern 
7,  3  and  9     Avenue,  each  of  these  alterna- 
tives would  be  entirely  under- 
ground.  This  would  allow  for 
greater  flexibility  in  develop- 
ment of  surface  land  uses  and  development 
parcels.   For  example,  it  may  be  possible  to 
retain  the  Sheraton  Building  by  underpinning 
the  structure  with  tunneling  under  the  building. 
The  aerial  connection  between  the  South 
split  alignment  and  the  existing  elevated 
Artery  would  be  avoided.   Community  impacts 
would  thus  become  considerably  more  positive 
in  this  area. 

South  of  the  Northern  Avenue  area,  the  poten- 
tial impacts  on  community  quality  and  charac- 
ter are  the  same  as  those  described  for 
Alternatives  4,5  and  6  above - 

Overall  Impacts 

Alternatives  1,  2  and  3  which  provide  only 
for  rebuilding  of  the  existing  facility  will 
have  continued  negative  traffic  and  environ- 
mental impacts  on  this  portion  of  the  Corridor. 
Difficult  traffic  movements,  both  on  the 
expressway  and  on  local  streets  will  continue 
to  affect  local  communities.  Without  further 
work  or  alterations ,  community  impacts  in  this 
area  will  include  spillover  of  traffic  onto 
local  streets  which  are  inadequate  to  handle 
the  demand. 

Alternatives  4  through  9  will  provide  a 
reconstructed  facility  to  reduce  congestion 
and  delays  in  the  area,  and  decrease  accidents 
on  expressways  and  local  streets.   Environmen- 
tal impacts  in  the  vicinity  will  be  significant- 
ly reduced  because  of  removal  of  certain  of 
the  transpo'rtation  impediments  which  exist 
today.   Opportunities  for  new  development  are 


115 


limited  -  appearing  principally  in  Alternati^-^s 
7,8  and  9  which  provide  new  parcels  adjacent 
to  some  of  the  most  actively  used  and  highly 
priced  lands  in  the  Commonwealth. 


:i.D.4 


Environmental  Impacts 

Air  Quality  Impacts 

The  proposed  changes  to  the  Central  Area 
which  potentially  affect  air  quality  in 
the  area  include: 

A-   Changes  in  traffic  volumes  and  speeds 
using  the  existing  expressway 
corridor  will  affect  gross  emissions 
areawide  under  all  alternatives. 

B.   Changes  in  pollutant  dispersion  would 
occur  throughout  the  South  Area,  if 
the  South  Section  of  the  Artery  is 
reconstructed  (Alternatives  4  through 
9) .   This  would  mean  the  enclosure 
within  a  tunnel  of  the  northbound 
lanes  of  the  highway,  and 
channeling  of  emissions  from  this 
•  section  into  additional  ventilation 
stacks.   These  new  stacks  would 
become  point  sources,  replacing  the 
existina  line  source  of  the  open  road- 
way. 


As  a  first-cut  estimate  of  air  quality 
impacts  of  the  South  Area  project, 
calculations  of  gross  pollutant  emissions 
were  carried  out  for  each  of  the  nine 
project  alternatives.   All  calculations  were 
performed  using  1975  A.M.  pea.k  traffic  vol- 
umes.  Emissions  factors  used  were  1975 
average  emissions  factors  from  the  EPA 
Compilation  document.  Supplement  5;  as  in 
the  No-Build  case  (defined  above  as  the 
"Existing"  air  quality  situation) ,  these 
emissions  factors  were  speed-corrected  to 
correspond  to  predicted  speeds  on  individual 
links.   The  resulting  emission  totals  of 
CO,  HC  and  NOj^  associated  with  all  alternatives 
are  presented  in  Figure  35. 

Generally  speaking,  all  of  the  reconstruc- 
tion alternatives  produce  smaller  quanti- 
ties of  CO  and  HC  emissions  than  the  No  Build 
alternatives;  e.g.,  Alternatives  4  and  7, 


which  include  no  additional  harbor  tunnel, 
are  preferable  to  Alternatives  1,2,  and  3 
in  terms  of  CO  and  HC  pollutant  burden. 
However,  the  No  Build  alternatives  emerge 
as  more  desirable  in  terms  of  NO   emissicno 
when  compared  with  the  reconstruction 
alternatives . 

Finally,  any  new  surface  ventilation  stacks 
which  are  required  to  accompany  roadway 
construction  in  tunnels  will  become  "point 
sources"  of  automotive  pollutants.   The 
design  and  location  of  such  stacks  for 
the  area  in  the  Fort  Point  Channel  (assuming 
the  South  Section  is  reconstructed  in 


Figure  35 

Gross  Pollutant  Emissions 
Central  Area  Alternatives 

Pollutant  Emissions 
tons/year 

Alternative  qq  ^q  NOx 

1  -  No  Build  4990     620      760 

2  -  No  Build  &  SP  4970     620      780 

3  -  No  Build  &  GP  5070     630    '  770 

4  -  South  only  3720     540      990 

5  -  South  &  SP  3010     490     1010 

6  -  South  &  GP  3020     490     1030. 

7  -  South  &  Central        3140     530     1270 

8  -  South  &  Central  &  sP   30OO     510     12in 

9  -  South  &  Central  &  GP   30OO     500     1210 

SP  =  special-purpose  third  harbor  crossing 
GP  =  general-purpose  third  harbor  crossing 

Variations'  among  the  alternatives  may  occ\ir 
because  of: 

-  differences  in  demand  associated  with 
capacity  differences  among  the  alternatives; 

-  changes  in  speeds  from  link  to  link  accord- 
ing to  capacity  and  demand  (emissions  of 
all  three  pollutants  are  speed  dependent) ; 

-  minor  differences  among  alternatives  in 
length  of  roadway,  resulting  in  changes  in 
overall  vehicle-miles  of  travel  even  when 
volxmies  are  constant. 

117 


txinnels,  as  proposed  in  Alternatives  4 
through  9)  as  well  as  the  detailed 
analysis  of  air  quality  impacts  of 
additional  stacks,  are  steps  to  be 
accomplished  at  a  later  stage  of  planning 
for  this  project. 

Noise  Impacts  ^    ^   -..t.  ^u 

Several  ot  tne  changes  associated  with  the 
various  South  Area  alternatives  have  the 
ootential  to  affect  noise  levels  in  adjacent 
areas.   These  changes,  and  their  like  effects, 
are  discussed  below. 

Throughout  the  South  Area  of  the  Artery, 
changes  in  traffic  -volumes  generated  by 
different  alternatives  result  in  relatively 
minor  increases  or  decreases  in  volumes 
traversing  individual  links;  these  changes 
should  have  little  or  no  effect  on  areawide 
noise  levels.   However,  many  of  the  existing 
ramps  and  expressway  access  would  be  re- 
constructed to  accomodate  the  proposed  Artery 
changes.   Such  design  changes  would  possibly 
cause  some  increases  or  decreases  m  noise 
levels  for  a  specific  street  corner,  row 
of  buildings,  etc.   These  changes  would  be 
both  minor  and  extremely  localized;  they 
can  more  properly  be  addressed  at  a  later 
stage  of  the  planning  process,  when  specific 
designs  for  such  connections  become  available. 

■^h-  South  Area  project  itself  probably 
will  not  cause  any  noticeable  increase  or 
Increase  in  noise  levels  in  the  corridor 
Noise  levels  are  already  so  high  that  the 
area  will  be  evaluated  in  terms  of  possible 
noise  abatement  measures,  which  can  be 
implemented  as  part  of  the  South  Area 
project. 

Water  Ouality  Impacts 

Alternatives  d, 2  and  3  ^i^^  P^°^^^^\^h  ""^rea 
change  in  water  quality  m  the  South  Area 
of  the  corridor.   Alternative  4  through 
9  which  recmire  the  construction  of  tunnels 
for  the  Artery  will  result  in  signiricanc 
changes  in  the  ways  in  which  water  is  now 
collected  and  carried  off  throughout  the 
corridor.   Following  construction,  all   _  _ 
alternatives  will  likely  result  in  a  positive 
impact  on  water  quality  as  a  consequence 
of  roadway  runoff  control.   Plans  for  the 
project  not  only  fit  with  overall  plans  to 


113 


improve  the  quality  of  water  runoff  within 
the  Downtown  area,  but  may  provide  an 
incentive  to  advance  the  plans  for  water 
outfall  treatment  and  control  through 
integrated  construction  of  the  highway 
and  water  pollution  control  facilities, 
particularly  in  the  Fort  Point  Channel. 

III.D.5    Costs,  Construction  Duration  and  Disruption 

Project  Life 

All  deck  replacement  work  anticipated  in 
the  alternatives  will  have  a  service  life  of 
30  years.  Ail  tunnel  construction  will  have 
a  service  life  of  40  years. 

Construction  Costs  -  South  Area 
Construction  costs  for  the  no-build 
alternatives  (1,2  and  3)  are  $10,640,000 
in  the  South  Area.   This  includes  only  the 
costs  of  concrete  deck  replacements  on  the 
existing  Artery  facility.  Modifications  to 
the  Dewey  Square  Tunnel  are  not  included  in 
this  estimate.  Construction  costs  for 
alternatives  4  through  9  -  the  split  align- 
ment alternatives  -  are  $190,580,000.  This 
includes  connections  into  the  existing 
facilities  on  the  extremeties  of  the  project, 
and  improvements  to  the  approaches  from 
expressways  and  local  streets. 

These  costs  are  only  for  improvements  to  the 
Artery  itself  in  the  South  Area,  and  exclude 
related  projects  such  as  the  third  harbor 
crossing  and  the  north  and  south  portions  of 
the  corridor.  The  costs  of  related  projects 
are  listed  below. 

Construction  Costs  -  Related  Projects 
Alternative  1  -  no  related  projects 
Alternative  2  -  Special  Purpose  Harbor 

Tunnel  from  Bradway  to  E. 

Boston  -  $407,940,000 
Alternative  3  -  General  Purpose  Harbor 

Tunnel  from  Broadway  to  E. 

Boston  -  $634,420,000 
Alternative  4  -  No  related  projects 
Alternative  5  -  Special  Purpose  Harbor 

Tunnel:  $312,760,000 
Alternative  6  -  General  Purpose  Harbor 

unnel:  $390,720,000 
Alternative  7  -  Reconstruction  of  the  Central 

Area  of  the  Artery: 

$1,015,000,000 


119 


Alternative  8  -  Reconstruction  of  the  Central 

Area  of  the  Artery: 
$1,015,000,000  and  Special 
Purpose  Harbor  Tunnel: 
$312,760,000 

Alternative  9  -  Reconstruction  of  the  Central 

Area  of  the  Artery: 
$1,015,000,000  and  General 
Purpose  Harbor  Tunnel:  . 
$390,720,000 

Note:  the  construction  cost  estimates  for 
the  Harbor  Tunnels  are  less  if  the  split 
alignment  of  the  Fort  Point  Channel  is  part 
of  the  South  Area  reconstruction  because  it 
includes  the  tunnel  approaches  between 
Broadway  and  the  Northern  Avenue  Bridge. 

Types  of  Construction  Disruption 
Alternatives    In  order  to  maintain  traffic 
1  2   and  3      on  the  expressways,  the  decks 
'  '  would  have  to  be  replaced  one 

lane  at  a  time.   This  would 
result  in  moderate  traffic 
disruption  for  the  duration  of 
the  construction  period.   If 
ramps  are  reconstructed,  the 
work  would  be  phased  jointly 
with  deck  replacement- 
Alternatives    Reconstruction  of  the  Artery, 
4  through  9     by  providing  new  tunnels  for 

the  roadway,  will  result  m 
disruption  only  at  the  locations 
where  connections  between  the 
new  tunnel  and  the  existing 
roadway  must  be  provided.  At 
such  locations,  the_  overall 
goal  is  to  disrupt  Artery  traffic  minimally. 
This  will  be  accomplished  by  making  replace- 
ment lanes  available  for  existing  traffic  at 
all  times  throughout  the  construction  period. 
Detailed  design  of  the  proposed  project  is   _ 
essential  to  determine  the  nature  of  disruption 
potential  and  the  mitigating  measures  which 
must  be  undertaken  to  modify  impacts  on  local 
communities,  local  and  expressway  traffic  and 
on  businesses  throughout  the  corridor. 


CHAPTER  IV.    PUBLIC  PARTICIPATION 


IV. A   PRCCESS 


Public  involvement  has  led  toward  the  develop- 
ment of  this  document,  as  an  integral  part  of 
the  process  of  discussing  issues  and  designing 
proposals  which  meet  community  needs .   The 
current  process  began  with  the  community  con- 
cerns about  the  construction  of  transportation 
improvements  in  the  area,  and  the  subsequent 
study  of  changes  to  the  Artery  carried  out 
through  the  Boston  Transportation  Planning 
Reviev;  and  a  subsequent  study  conducted  by 
the  Boston  Redevelopment  Authority  for  the 
Mass.  Department  of  Public  Works. 


iv.B   PUBLIC  INVOLVEMENT  PROGRAM 


A  slide  show  was  developed  to  provide  infor- 
mation to  the  public  on  the  overall  program 
for  proposed  improvements  to  the  Artery  corri- 
dor and  to  generate  comment  from  concerned 
citizens.   The  slide  show  has  been  presented 
to  interested  community  groups  and  individuals , 
public  agencies  and  responsible  officials,  and 
organizations  with  regional  focus. 

A  working  committee  of  local  and  regional  in- 
terests was  established  to  review  the  proposed 
improvements  to  the  Artery  corridor.  A  selected 
list  of  representatives  from  the  South  Area  was 
developed  and  is  now  included  on  all  mailings , 
literature  distributions,  and  invitations   to 
working  committee  and  other  public  meetings. 

In  addition  to  the  slide  show  and  working  com- 
mittee meetings,  special  briefings  have  been 
held  with  specific  interests  in  proposed  South 
Area  improvements.   They  include  Boston  city 
officials,  property  owners,  private  organiza- 
tions ,  and  agencies  which  have  a  interest  in 
the  area,  such  as  MassPort  and  the  Mass.  Turn- 
pike Authority. 

Through  the  above  activities ,   a   draft  Corri- 
dor Planning  Study    was    prepared  for  the 
South  Area.  This  document  was  distributed  to 
key  community  representatives,  discussed  in 
briefings,  distributed  to  regional  organiza- 
tions and  public  agencies  and  was  the  subject 


121 


of  a  working  committee  meeting  on  October  17, 
1977.   Comments  resulting  from  meetings  have 
been  incorporated  into  this  chapter  and  other 
parts  of  this  document.   A  detailed  listing 
of  comments  is  included  in  this  chapter. 


IV. C   PUBLIC  COMMENTS  AND  RESPONSES 


South  End  Community  Review  -  September  29,  19  7  7 

Comments  were  made  on  the  comprehensiveness  of 
the  document,  with  suggestions  that  mention 
should  be  made  of: 

1.  Problems  of  the  present  ramps  leading  between 
E.  Berkeley  Street  and  the  Artery. 

2.  The  Artery  congestion  causes  through  traffic 
to  seek  local  street  alternative  routes. 

3.  The  Artery  prohibits  direct  connections 
between  the  South  End  and  South  Boston,  partic- 
ularly for  buses . 

4.  The  aesthetics  of  the  Artery  are  of  concern. 

5.  There  is  no  local  service  provided  by  the 
Turnpike. 

6.  The  three-lane  bridge  on  the  Artery  at  the 
Massachusetts  Avenue  interchange  is  a  bottleneck 
between  the  Artery  and  the  Southeast  Expressway. 

7.  There  is  an  existing  agreement  between  the 
South  End  Committee  on  Transportation  and  the 
City  of  Boston  in  regard  to  the  use  of  local 
streets  for  through  movements . 

8.  The  routes  for  traffic  during  construction 
in  the  no  build  options  should  'be  outlined. 

9.  The  environmental  and  engineering  analysis 
should  include:   a.   noise  impacts  on  housing 
abutting  Albany  Street  and  the  hospitals, 
perhaps  also  New  England  Nuclear  and  Gillette; 
b.   economic  benefit  analysis  of  a  more  rational 
truck  access  pattern  which  does  not  impact 
residential  communities;  c.   definition  of 
project  boundaries  to  include  all  of  the  Massa- 
chusetts Avenue  interchange  with  the  Artery; 

d.   capacity  analysis  to  assure  that  initial 
construction  with  provision  for  construction  of 


a  Third  Harbor  Crossing  does  not  attract  excess 
traffic,  along  with  examination  of  ways  and  means 
of  retaining  present  traffic  volumes  with  no 
increases;  e.   local  and  regional  energy  uses; 
f.   value  capture  through  improvements  and 
analysis  of  who  benefits  and  pays;  g.   inter- 
relation with  the  Southeast  Expressway;  h.  less 
optimistic  air  quality  analysis. 

This  question  was  answered  by  a  statement  that 
re-uses  of  the  surface  can  be  included  in  the 
environmental  and  engineering  work  which  is  to 
be  done-   It  is  a  subject  that  can  be  resolved 
only  with  more  examination  of  the  surface 
street  needs  and  engineering  analysis  of  the 
bearing  capacity  of  the  present  tunnel. 

2.  Where  is  the  parking  access  to  the  new 
South  Station  complex  to  be  provided? 

All  access  to  South  Station  parking  is  present- 
ly planned  to  be  accomodated  on  Atlantic 
Avenue . 

3.  Which  alternative  does  the  State  prefer? 
The  present  corridor  location  is  preferred, 
but.  the  specific  alternative  has  not  been 
determined,  pending  additional-  information. 

4.  Why  have  the  ramps  in  the  existing  tunnel 
been  closed? 

The  ramps  have  been  closed  for  safety  reasons. 

5.  What  guarantees  do  we  have  that  the  develop- 
ment of  the  plans  will  not  encroach  upon 
Chinatown,  even  though  they  do  not  do  so  at 
present? 

The  state  has  no  intention  of  further  encroach- 
ing on  Chinatown;  decisions  on  alternative 
designs  will  be  the  subject  of  more  detailed 
analyses  including  additional  community  meet- 
ings and  review  sessions. 

6.  ^<lhat   do  the  developers  around  the  Fort 
Point  Channel  think  of  the  prooosal  for  a  new 
tunnel? 

To  date,  the  property  owners  and  business  peo- 
ple appear  to  be  positive  toward  the  proposal 
no  objections  have  been  raised  to  the  proposal 
as  presently  developed. 

Central  Artery  Working  Committee  -  Oct.  17,  1977 

An  overview  of  the  progress  of  all  aspects  of 
the  Artery  work  was  presented,  followed  by 
an  invitiation  for  comments  and  criticism  of 


123 


the  South  Area  Corridor  Planning  Study. 
Questions  were  raised  as  follows: 

1.  What  are  the  Third  Harbor  Crossing  conclu- 
sions?  Response:  a  full  scale  traffic  analysis 
is  envisioned  in  subsequent  environmental  and 
engineering  work  to  ascertain  potential  volumes 
and  traffic  impacts  on  South  Area  proposals. 

2.  Are  there  any  further  specific  designs  on 
the  Fort  Point  Channel  alianment?  Response:  No 

Major  concerns  about  the  alignment  are  principally 

the  environmental  impacts  and  the  considerations 

of  the  existing  red  line  transit  tunnel  in 

the  channel.  Most  of  the  Boston  Conservation 

Commission  objectives  have  been  met  in  improving 
the  water'-s  edge. 

3.  Which  part  of  the  proposal  is  in  the  Channel, 
and  which  part  on  land?   Response:  this  will 
become  a  major  part  of  the  detailed  work  ahead; 
further  details  have  not  yet  been  developed  . 

4.  Will  the  consultants  for  the  South  Area 
analyze . these  alternatives?   Response:  yes. 

5.  What  is  the  relationship  to  the  proposed 
Seaport  Access  Road?   Response :  both  are 
physically  and  functionally  related.   The 
Seaport  Access  Road  is  currently  undergoing 
environmental  analysis,  with  5  alternatives 
derived  from  the  initial  work.  The  project 
is  briefly  covered  on  page  76. 

fc .  What  are  the  negative  impacts  on  the  Fort 
Point  Channel?   Response:   the  channel  may  be 
narrowed;  the  proposed  tunnel  may  not  be  below 
water  level,  because  of  the  need  to  pass  over 
the  existing  Red  Line  transit  tunnel;  post 
office  operations  are  a  major  constraint  on 
alignment  choices. 

7.  What  are  the  positive  impacts  on  the  Fort 
Point  Channel?   Response:  development  on  the 
edge  of  the  channel  -  a  park  strip,  pedestrian 
way,  marina,  etc.;  cleanup  of  the  present  sewer 
outfalls  into  the  channel. 

8.  Will  the  South  Area  consultant  be  concerned 
with  urban  design.   Response:  absolutely. 

9.  Where  are  the  locations  for  a  potential 
arena?   Response:   locations  being  considered 
are  south  of  Summer  Street. 

10.  What  about  longer  range  land  uses,  especi- 
ally air  rights  over  the  Expressway?   Response: 


air  rights  development  is  not  out  of  the  ques- 
tion, but  may  be  difficult  in  areas  such  as 
the  interchange  with  the  Turnpike. 

11.  Does  the  document  relate  the  South  Area 
proposals  with  the  South  Station  plans? 
Response:   it  provides  for  the  eventual  and 
the  short-range  improvements  to  South  Station. 

12.  What  is  the  year  for  the  projected  benefits 
of  the  various  proposals?  Response:   the  year 
of  opening;  this  has  been  added  to  the  text. 

13.  What  is  the  level  of  federal  support  for 
this  work?   Response:  federal  review  of  this 
and  other  such  documents  will  lead  toward  EIS 
work;  there  have  been  no  indications  that 
they  will  not  allow  EIS  work  following  accept- 
able documentation  of  corridor  planning  studies. 

14.  Will  you  be  having  additional  community 
meetings?   Response:   the  community  review 
process  will  continue  for  these  documents  through 
November   and  December,  with  a  more  complete 
involvement  process  if  the  documents  are 
approved  by  the  federal  government.. 

15.  The  Southeast  Expressway  work  is  being 
done  without  community  participation;  expan- 
sion of  the  expressway  capacity,  especially 
inbound  must  have  participation,  and  study  of 
what  can  be  done  at,  for  example,  the  Berke- 
ley Street  ramps.   What  is  the  process  to 
obtain  community  involvement  in  this  area? 
Response:   The  Mass.  DPW  is  reviewing  current- 
ly the  possibility  of  looking  at  a  lane  con- 
figuration for  the  Southeast  Expressway  that 
would  be  3-2-3  instead  of  the  present  3-3 
with  breakdown  lanes.   If  this  is  to  be ^ 
extensively  examined  there  will  be  public 
hearings  on  the  proposals. 

16.  If  the  entire  Artery  project  is  built, 

in  North,  South  and  Central  Areas,  where  will 
future  bottlenecks  occur?   Response:   none 
in  the  North  are  foreseen;  some  may  remain 
in  the  South  because  of  the  restricted 
capacity  of  the  Southeast  Expressway.   This 
will  need  close  examination. 

17.  General  comments  for  possible  additions 
to  text : 

Albany  Street  will  be  a  major  bypass  while 
construction  is  being  undertaken,  because 


125 


there  is  no  connection  between  City  Hospital 
and  the  northbound  Artery  access  roads. 
Reference  should  be  made  that  the  present 
interchange  at  Mass.  Ave.  is  substandard, 
and  must  be  rebuilt,  even  in  a  no-build  alt- 
ernative. 

There  is  serious  question,  from  a  neighbor- 
hood point-of-view,  that  capacity  should  be 
increased  in  the  area.   Traffic  might  be 
metered  into  town,  for  example,  at  the 
Braintree  entry  point  to  the  Southeast  Ex- 
pressway.  Three  lanes  in  and  four  lanes  out 
of  town  should  be  examined.   The  question 
should  be  examined  as  a  policy  issue;  there 
may  be  an  upper  limit  on  traffic  in  the  whole 
corridor.   Transit  may  have  more  to  do  with 
limiting  traffic  than  what  is  done  to  improve 
this  road. 

There  are  existing  agreements  between  the  City 
and  its  neighborhoods  that  must  be  acknowledged 
in  planning  Artery  improvements.   Impacts  are 
too  often  posed  in  terms  of  level  of  traffic 
service  vs.  community  impacts;  a  low  level  of 
service  in  Braintree  may  be  best  for  this  area, 
to  deter  traffic  from  entering  the  corridor. 
Most  radial  traffic  may  be  to  the  Southwest  - 
not  the  Southeast.  -  thereby  putting  pressure 
on  the  local  streets  which  connect  with  the 
Artery  in  the  vicinity  of  Mass.  Ave.   This 
pressure  may  have  been  underestimated.. 
An  additional  alternative  alignment  for  the 
Artery  in  the  rail  yards  south  of  South  Stat- 
ion  (betwen  the  city  public  works  building 
and  the  MBTS  yards)  should  be  examined. 
The  projectneeds  to  relate  traffic  problems 
to  the  potential  changes  in  life  styles;  how 
can  impacts  be  reduced,  and  how  can  auto 
dependence  be  reduced. 

All  of  the  above  comments  in  item  17  may  be 
more  appropriately  dealt  with  in  the  EIS  work 
which  is  yet  to  come. 


Comments  received  in  Questions  1  through  9 
have  been  incorporated  into  the  body  of  the 
report  as  appropriate.   Questions  1  through 
4  are  dealt  with  in  revisions  in  the  text 
on  pages  19  through  23.   Question  6  is 
discussed  on  page  64.   Other  questions  have 
been  noted  for  future  analyses. 


Dewey  Square  Study  Committee  -  Oct.  6,  1977 

At  this  meeting  of  the  several  property  owners 
and  businesspeople  in  the  area  surrounding 
Dewey  Square  and  South  Station,  a  brief  presen- 
tation followed  earlier  discussions  of  a  pro- 
posed new  arena  and  South  Station  plans.  All 
planning  for  the  area  is  now  proceeding  on 
the  basis  of  the  Mass.  DPW  alignment  for  a 
new  Fort  Point  Channel  Tunnel  for  northbound 
Artery  traffic.    It  was  noted  that  a  new 
arena  would  require  substantial  public  invest- 
ments  for  connections  into  the  Artery  improve- 
ments.  The  South  Station  proposal  now  being 
advanced  does  not  require  separate  Artery  ramps; 
access  for  vehicles  to  and  from  parking  will 
take  place  on  Atlantic  Avenue. 

Because  of  the  extensive  number  of  items  on  the 
agenda,  there  was  little  time  for  questions.  One 
questions  was  posited:  does  the  Sheraton  Build- 
ing have  to  be  taken  in  all  alternatives? 
The  questions  was  answered  with  reference  to 
pages  113  and  114  of  this  document.   The 
building  can  be  retained  by  underpinning  in 
Alternatives  7,8  and  9. 

Chinatown  Community  Review  -  Oct.  13,  1977 

A  meeting  of  the  Chinese  Benevolent  Association 
included  an  opportunity  for  presentation  and 
review  of  the  Corridor  Planning  document  with 
a  large  number  of  Chinatown  community  leaders. 
The  presentation  was  made  orally,  chapter  by 
chapter,  with  translation  following  each  para- 
graph.  Copies  of  the  document  were  made  avail- 
able for  siobsequent  individual  review. 

Questions  which  were  asked  included  the  follow- 
ing: ■ 

1.  What  is  the  potential  for  re-use  of  the 
present  surface  Artery  in  the  reconstruction 
proposals?  Can  it  be  returned  to  the  Chinese 
community?   Is  it  possible  to  build  over  the 
present  tunnel  with  small  one-story  shops  or 
open  space? 

This  question  was  answered  by  a  statement  that 
re-uses  of  the  surface  can  be  included  in  the 
environmental  and  engineering  work  which  is  to 
be  done.   It  is  a  subject  that  can  be  resolved 
only  with  more  examination  of  the  surface 
street  needs  and  engineering  analysis  of  the 
bearing  capacity  of  the  present  tunnel. 


127 


2.  Where  is  the  parking  access  to  the  new 
South  Station  complex  to  be  provided? 

All  access  to  South  Station  parking  is  present- 
ly planned  to  be  accomodated  on  Atlantic 
Avenue . 

3.  Which  alternative  does  the  State  prefer? 
The  present  corridor  location  is  preferred, 
but  the  specific  alternative  has  not  been 
deter ined,  pending  additional  information. 

4.  Why  have  the  ramps  in  the  existing  tunnel 
been  closed? 

The  ramps  have  been  closed  for  safety  reasons. 

5 .  What  guarantees  do  we  have  that  the  develop- 
ment of  the  plans  will  not  encroach  upon 
Chinatown ,  even  though  they  do  not  do  so  at 
present? 

The  state  has  no  intention  of  further  encroach- 
ing on  Chinatown;  decisions  on  alternative 
designs  will  be  the  subject  of  more  detailed 
analyses  including  additional  community  meet- 
ings and  review  sessions - 

6 .  What  do  the  developers  around  the  Fort 
Point  Channel  thing  of  the  proposal  for  a  new 
tunnel? 

To  date,  the  property  owners  and  business  peo- 
ple appear  to  be  positive  toward  the  proposal' 
no  objections  have  been  raised  to  the  proposal 
as  presently  developed. 


CHAPTER    V:    CONCLUSIONS  &   RECOMMENDATIONS 


Improvements  to  portions  of  the  South 
Area  of  the  Central  Artery  will  have 
to  be  undertaken  within  the  near  future. 
These  improvements  are  principally 
deck  replacements  on  the  expressway 
in  the  area  of  the  corridor  south  of 
the  Dewey  Square  Tunnel.  These  decks 
are  deteriorating  and  will  need 
replacement  if  no  other  work  is  undertaken, 
in  the  corridor.   However,  there  are 
substantial  problems  in  the  operations 
of  the  present  facility  which  should  be 
examined  to  determine  the  appropriate 
course  of  action. 

Operational  problems  of  the  present 
facility  in  the  South  Area  must  be 
solved  within  the  present  corridor. 
There  are  no  feasible  alternatives  to 
the  present  corridor  in  which  a  new 
or  bypass  facility  can  be  located. 
Alternatives  to  the  present  corridor 
have  been  examined  for  all  alignments 
which  have  been  discussed  in  past  or 
present  contexts;  none  of  the  alternative 
corridors  provides  a  feasible  location  for 
a  new  facility. 

Within  the  present  corridor,  there  are 
few  alternatives  which  improve 
operations  of  the  South  Area  of  the 
Artery  without  extensive  negative 
environmental  impacts.   Widening  the 
present  Dewey  Square  Tunnel,  for  example, 
is  not  an  acceptable  solution  from  a 
community  or  land  damage  viewpoint. 
Double-decking  the  tunnel  is  likewise 
infeasible.   Existing  land  uses  and 
proposed  new  developments  constrain 
alternative  locations  for  improvements. 
Two  basic  alternatives  have  emerged:   the 
no  build  which  provides  for  upgrading 
the  present  facility;  and  a  reconstruction 
which  includes  a  new  facility  in  either  the 
Fort  Point  Channel  or  under  Atlantic  Avenue 
to  provide  for  northbound  movement ,  and  a 
modified  Dewey  Square  Tunnel  for  southbound 
movement.  These  alternatives  have  been 
examined  in  detail  particularly  with  respect 
to  their  relationship  to  projects  external 
to  the  South  Area;  i.e.,  the  proposed  im- 
provements to  the  Central  Area  of  the  Artery 
Corridor  and  a  proposed  Third  Harbor  Tunnel,  for 


129 


either  general  or  special  pxirpose  use. 
This  analysis  led  to  the  examination  of 
nine  possible  alternatives. 

Feasible  Alternatives  for  South  Area 

The  chart  below  shows  the  alternative 
permutations  which  are  possible  in  the 
South  Area  of  the  Artery  corridor 
Alternative  1  is  the  basic  No  Build 
Alternative-with  Alternatives  2  and  3 
as  permutations.   Alternative  4  is  the 
basic  reconstruction  alternative  with 
alternatives  5,6,7,8  and  9  as  permutations. 


Flgxire  36:  South  Area  Alternatives 


Without 
3rd  H.C. 

With  3rd  Harbor  Crossing 

Special 
PurDose 

General 
P\ir-Dose 

NO  BUILD 

Alt.  1 

Alt.  2 

Alt.  3 

SPLIT  ALIGNMENT 
VTETHOUT  CENTRAL 
AREA 

Alt.  4 

Alt.  5 

Alt.  6 

SPLIT  ALIGNMENT 
WITH  CENTRAL 
AREA 

Alt.  7 

Alt.  8 

Alt.  9 

The  No-Build  Alternatives 


Alternative  1,  with  deck  replacement  as 
its  major  feature,  has  two  variations- 
Alternatives  2  and  3  -  which  include  deck 
replacement  in  combination  with  previously 
developed  alignments  for  a  third  harbor 
t\innel  project.   Alternatives  2  and  3  were 
examined  because:   1.  previous  alternatives 
for  a  third  harbor  tunnel  required  study 
in  relation  to  more  c\irrent  thinking  about 
improvements  in  the  South  Area;   2.   these 
alternatives  are-  useful  analytically  for 
comparing  Artery  improvements  with  an  inde- 
pendent Third  Harbor  Tunnel.   Previous  studies 
of  a  Third  Harbor  Tunnel  identified  the  Fort 
Point  Channel  as  the  most  feasible  location 


for  such  a  facility-   Hovw'ever,  use  of  the 
Channel  for  •&   Third  Harbor  1-unnel,  as  in 
Alternatives  2  and  3,  would  foreclose  South 
Area  Split  Alignment  alternatives,  whereas 
Alternatives  4  through  9  can  be  used  for 
Artery  improvements  while  preserving  the 
option  for  connections  to  a  Third  Harbor 
Tunnel  at  a  later  date.  Alternatives  2  and 
3,  which  do  not  improve  the  South  Area  with 
the  independent  Third  Harbor  Tunnel,  cost 
approximately  the  same  ($600,000,000)  as 
the  proposed  South  Area  Split  Alignment 
plus  a  Third  Harbor  Tunnel  which  connects 
to  it.  Because  Alternatives  2  and  3  fore- 
close options  and  do  not  make  Artery  improve- 
ments beyond  those  xn   Alternative  1,  they 
should  be  dropped  from  further  consideration 
as  potential  solutions  for  the  South  Area 
of  the  Artery^   Alternative  1  should  be    . 
retained  for  further  study.   If  Alternative 
1  IS  selected  for  xmplementation,  the  question 
of  a  Third  Harbor  Tunnel  can  be  examined  on 
its  own  merits  as  a  separate  project. 

Tie  con  struct  ion  Alternatives 

Alternatives  4  through  9  represent  the  various 
possibilities  of  a  full  reconstruction  of  the 
South  Area  for  Artery  improvements.  Alternative 
4  is  the  basic  alternative  for  reconstruction ; 
Alternatives  5  through  9  are  permutations  which 
have  been  included  to  afford  a  basis  for  analysis 
of  the  reconstruction  as  it  might  relate  to 
subsequent  or  concurrent  related  projects.  Anal- 
ysis of  Alternative  4  has  shown  that  it  is 
possible  to  construct  a  new  facility  which  would 
improve  the  transportation  operations  of  the 
South  Area  and  which  would  be  compatible  with 
concurrent  or  subsequent  development  of  related 
projects.   Permutations  of  Alternative  4  which 
include  a  Third  Harbor  Tunnel,  but  which  are 
otherwise  identical  to  Alternative  4,  are  Alter- 
natives 5  and  6.   Central  Area  Artery  improvements 
are  included  in  Alternative  7.   Alternatives  8 
and  9  are  permutations  of  Alternative  7  which  in- 
clude a  Third  Harbor  Tunnel,  but  are  otherwise 
identical  to  Alternative  7.   Of  the  six  recon- 
struction alternatives  (4  through  9) ,  it  is  recom- 
mended that  Alternatives  5,6,  8  and  9  be  elimina- 
ted from  further  environmental  and  engineering 
studies  in  connection  with  the  Central  Area  and 
thac  Alternatives  4  and  7  be  carried  into  further 
engineering  and  environmental  analysis.   They 
address  South  Area  transportation  problems  and 
potential  interactions  between  South  Area  Artery 


improvements  and  other  projects,  while  allowing 
for  the  potential  later  addition  of  a  Third  Harbor 
Tunnel  as  a  separately  built,  but  physically  con- 
nected future  project. 

It  should  be  noted  that  the  improvements  to 
the  Central  Area  of  the  Artery  corridor  and 
the  construction  of  a  Third  Harbor  Tunnel  are 
separate  projects,  serving  purposes  and  having 
benefits  which  are  different  from  the  recon- 
struction of  the  South  Area  of  the  Artery 
corridor.   South  Area  benefits  which  can  be 
achieved  include  provision  of  three  lanes  in 
each  direction  with  a  shoulder  in  each  direc- 
tion used  in  peak  periods;  fewer  ramps  to  and 
from  the  Artery  with  better  spacing  between 
ramps;  provision  of  speed  change  lanes  for 
ramp  traffic;  surface  frontage  roads  for 
collection  and  distribution  of  local  traffic; 
and  land  for  development  on  the  decks  over  the 
new  tunnels.   The  alternatives  which  have  been 
developed  for  the  South  Area,  and  which  should 
be  carried  forward  (Alternatives  1,  4  and  7) 
have  inherent  flexibility  to  accomodate  relat- 
ed projects  while  accomodating  South  Area 
needs. 


Major  reconstruction  of  the  South  Area  of  the 
Axtery  offers  the  possibility  of  implementing 
a  long-range  strategy  for  the  improvement  of 
the  economic  future  of  Downtown  Boston.  The 
Artery  affects  the  economic  vitality  of  all 
of  Downtown  Boston,  which  is  not  only  the  core 
of  the  metropolitan  area,   but  the  economic  and 
cultural  focus  of  the  New  England  Region.  The 
proposed  improvement  alternatives  affect  both 
the* local  community  and  metropolitan  and  New 
England  Regions  in  different  ways. 


Detailed  analysis  of  each  of  the  alternatives 
is  necessary.   In  particular  the 
follovinQ  tasks  should  receive ~s"pecial 
attention. 

a.   All  alternatives  require  detailed 
analysis  of: 

-  construction  techniques  and 
phasing 

-  traffic,  maintenance  during 
construction 

-  transportation  service 


demand/capacity  analyses 

surface  street  iinpacts 

relation  to  harbor  crossing 

demand  and  airport  service 

safety  during  and  after 

construction 

social  iinpacts  (regional 

and  local)  during  and  after 

construction 

social  impacts  to  adjacent 

neighborhoods  and  the  region, 

during  and  after  construction 

land  use  and  urban  design 

considerations 

detailed  cost  estimates 

en^loyment  generation 


b.      Reconstruction   alternatives    require, 
in   addition,    detailed  anailyses   of: 

-  ventilation  requirements 

-  joint  developnent  oppor- 
txonities 

-  decking  requirements 
tunnelling  requirements 

-  dangerous  cargo  handling 
joint  rail  line  construction 
rail  line  service,  space 
requirements 

Anticipated  Federal  Funding  Participation 

1-9  3  is  the  principal  North- South  route 
connecting,  in  the  NDrth,  the  Boston 
Metropolitan  Area  to  the  .Merrimac  Valley 
(Lowell  and  Lawrence),  New  Hampshire, 
Vermont  and  Canada.   To  the  south,  it 
connects  the  iaetropolitan  area  to  the 
southeast  area  of  the  Commonwealth,  Cape 
Cod  ,  Rhode  Island,  and  the  eastern 
seaboard.   1-90,  the  iMassachusetts  Turnpike, 
a  toll  facility,  connects  the  metropolitan 
"area  with  the  western  Massachusetts 
metropolitan  area  of  Worcester  and 
Springfield,  New  York  State,  and  states 
west  of  New  York.   Traffic  problems 
associated  with  the  interchange  of 
these  two  roadways  are  documented  in 
this  report.   Volumes  of  traffic  on  1-9  3 
approximate  135,000  ADT;  on  1-90, 
60,000  ADT. 


133 


Certain  alternatives  described  in  this 
document  would  require  the  addition, 
removal  and/or  realignment  of  certain 
ramp  connections  between  these  two 
major  interstate  routes.   Replacement  . 
"in-kind"  is  anticipated. 

Any  federally-aided  highway  is  subject  to 
the  requirement  in  Section  301  of  Title 
2  3,  United  States  Code,  Highways,  that 
it  be  free  from  tolls  (except  for 
certain  toll  bridges  and  tunnels  as 
provided  in  Section  129).   This  require- 
ment is  iret-   There  is  no  intention  of 
imposing  tolls  on  1-9  3,  nor  are  motorists 
using  1-93  required  to  exit  through  the 
1-90  tolls.   A  large  portion  of  1-9  3 
traffic  is  not  interchanging  with  the 
Massachusetts  Turnpike.   While  the  1-9  3/ 
1-90  connection  provides  a  major  transj.er 
of  traffic  between  the  two  interstate 
facilities,  1-93  as  part  of  the  interstate 
system  is  an  essential  through  route  and 
the  major  highway  in  the  City  of  Boston.  As 
long  as  the  present  interchange  is  not 
improved,  motorists  on  1-93  will  continue 
to  experience  severe  traffic  problems 
from  operational  and  safety  viewpoints. 
If  certain  alternatives  described  were 
solely  improvements  for  an  approach  to 
or  from  a  toll  facility,  then  that 
particular  alternative  would  not  be 
eligible  for  federal  partcipation.  This 
is  not  the  case  here. 

The  improvements  described  in  all 
alternatives  are  mainly  to  improve 
traffic  operational  conditions  on  1-93, 
not  I-96T  In  view  of  this,  it  is  the 
^^IHlQn~of  the" Department  of  Public  Works 
that  the  formula  for  funding  the  chosen 
"alternative  be  on  an  Interstate  90:TD 
basis. 


APPENDIX    I 

Previous   Studies   Related   to    the 
South  Area  of   the   Artery   Corridor 

Over   the  past   15   years    there   have   been 
many   studies   of   the    transportation 
problems   of   the   South  Area  of   the 
Artery   corridor.      These   have   resulted 
in   improvements    for  some   situations   and 
a  backlog  of  attempts    to   correct 
certain  of   the  Artery  problems.      The 
following  is   a   compendium  of   the   studies 
and  subsequent  action  which  has    resulted 
from  the   studies. 

1.      Relocated  Dorchester  Avenue.      In    1967, 
studies   were    conducted   for   the   MDPW 
to   determine   the    feasibility  of 
widening  the   existing  Dorchester 
Avenue.      The   proposed   improvement 
was    for  a  six-lane   roadway   in   the 
Fort   Point   Channel,    adjacent   to 
existing  Dorchester  Avenue.      The 
proposal   included   filling  Fort  Point 
Channel   and  several   alternative 
construction   techniques  were   examined 
in  order   to   minimize    impacts   on    the 
existing  Red  Line   rapid  transit 
tunnels   in   the   middle   of   the   Channel. 
The   proposal   required   use   of   the   Fort 
Point  Channel   alignment,    even    though 
special   measures  would  have    to  be 
taken   to  protect   the   Red  Line    timnels. 
Dorchester  Avenue,  if   improved,  would 
extend   to   Northern  Avenue    from  its 
existing  terminus    at   the   bridge  over 
the   Channel   in   South  Boston.         The 
present   right-of-way   of   Dorchester 
Avenue   would  not  be    used   for  new 
improvements,    owing   to   its    sale    to 
the   U.S.    Post  Office   Department.      After 
consideration  of   the  proposal   and   its 
potential   conflicts  with  proposed 
land  uses   along  the  channel,    it  was 
dropped   from  further  consideration. 

2.      Third  Harbor  Crossing    (Howard, Needles , 
Tammen,    Bergendof f , 1968)       This    study, 
directed   to  be    undertaken   by   the 
Massachusetts    Legislature,    recommended 
a   six-lane   general -purpose    tunnel    to 


135 


be   operated  as   a   toll   facility.      The 
alignment  chosen  was   the   Fort  Poxnt 
Channel   on   the  downtown   =^^^^°^^^^^^^ 
harbor,    to  East  Boston  on   the   railroaa 
alignment  through   the   middle   of   the 
community,    with   connections   to   C-1 
at   the   entrance   to   the  airport.      The 
proposal  elicited  much   adverse   comment 
?rom  the   community,    and   led   to   the   need 
for   further  examination  of   the  Potential 
alignment  and  demand  for  the   facility. 
This  work  was   done   in  the   Boston 
Transportation  Planning  Review. 

Harbor  crossing.      The  Boston   Transpor- 
tation   Planning   Review  examined 
proposals    for  a  third  harbor   crossing 
between  E.    Boston/Logan  Airport  and 
Downtown   Boston.      General    -   and 
special   -  purpose   tunnels  were 
examined  on  various   alignments.      Some 
alternatives    included  provision    for 
related  operations   and  service 
improvements,    such   as    satellite 
parking,    rapid   transit   improvements, 
bus-limo   service,    street  improvements 
and  high-speed   rail   in  the   NE   corridor  _ 
The  basic   alternatives  were:       (1)    a   six 
lane   general-purpose    tunnel   from 
downtown    to   the  airport   and  north  to 
connect  to   a  new  expressway   serving 
the  north   and  north   shore;     (2)    a   2- 
lane   special-purpose    tunnel  between 
downtown   and   the  airport  and  no  new 
harbor  crossing,    but   improved   rail,    bus/ 
limo   service   and  satellite  parking;    and 
(3)    a  NO  Build  Alternative,    with  Central 
Artery   improvements   including  bus 
rights-of-way   to   the   Sumner   and 
Callahan  Tunnels   along  with  maior 
transit   and  service   improvements.     . 

At  the  conclusion  of   the  study,    the 
then   governor   recommended  the    _ 
construction  of   a   two-way   special- 
purpose    tunnel   in  an   alignment   in   the 
Fort  Point   Channel   crossing   the   harbor 
and  surfacing  on   airport  property   to 
terminate   at  the   airport  service   road. 
This   tunnel  was   intended   to   serve   only 
buses,    limos,    trucks,    emergency 
vehicles   and   taxis.       It  was   also    _ 
intended  to  be   supplemented  by  ma^or 
transit   improvements    and  by   satellite 
terminals    for  park-and-ride  between 
s\iburbs   and  airport.      After 


presentation  and  deliberation  by  the 
state  legislature,  no  approval  was 
granted  to  proceed  with  the  tunnel. 

Deck  Reconstruction — Southeast  Expressway 
Reconstruction  of  deteriorating  highway 
decks  on  the  Southeast  Expressway  was 
first  suggested  in  19  73.   The  original 
proposals  called  for  replacement  of 
all  decks  on  the  Southeast  Expressway 
bridges.   Two  areas  of  concern  were 
located  within  the  South  Area  of  the 
Artery  corridor:   approaches  to  both  the 
Dewey  Square  Tunnel  and  the  Massachusetts 
Avenue  interchange,  which  are  on 
elevated  structures.   Because  of  the 
extent  of  deterioration,  the  Massachusetts 
Avenue  interchange  work  is  now  under 
construction.   However,  deck  replacement 
at  other  locations  within  the  South 
Area  has  been  postponed  because  of  its 
potential  relationship  to  the  Central 
Artery  project  in  the  South  Area.   Along 
with  the  deck  reconstruction,  other 
operational  efforts  are  underway  to 
improve  capacity  and  flow  on  the  Southeast 
Expressway,  both  during  and  after 
construction.   These  include  preferential 
bus  and  carpocl  lanes  during  rush  hours 
and  in  peak  direction,  and  the  state 
program  to  encouraae  use  of  transit  and 
carpools. 

Massachusetts  Turnpike  Frontage  Roads. 
The  BRA  recommended  in  a  19  74  statement 
of  South  End  transportation  issues  "a 
state-sponsored  environmental  assessment 
and  basic  design  of  alternatives  for 
completing  a  Turnpike  frontage  road 
system  from  Dorchester  Avenue  and  the 
Southeast  Expressway  to  Dartmouth  Street." 
This  would  involve  a  connection  of 
Broadway  with  Marginal  Road  and  an 
extension  of  Herald  Street  from  Arlington 
Street  to  Dartmouth  Street,  along  with 
related  street  modifications.   The   road 
would  serve  to  remove  truck  traffic  from 
congested  South  End  residential  streets. 

South  Boston  Seaport  Access  Road.  In 
September  1976,  the  BRA  and  Massport 
selected  a  consultant  to  prepare  a 
draft  environmental  assessment  for  a 
seaport  access  road  in  South  Boston. 

137 


Currently,  industrial  truck  traffic 
randomly  utilizes  the  South  Boston 
local  street  system  in  seeking  access 
to  the  Castle  Island  container  terminal 
and  other  industrial  or  commercial  areas 
located  north  of  West  First  Street.   The 
seaport  access  road  has  been  proposed  to 
end  intrusion  of  industrial  traffic  onto 
residential  streets  and  improve  the 
potential  for  development  of  South 
Boston's  600  acres  of  underused  and  vacant 
land.   It  would  supplement  joint  private 
and  public  efforts  to  revitalize 
existing  commercial  and  industrial 
properties  in  the  area  north  of  First 
Street  and  west  of  Summer  Street. 

7.  New  Northern  Avenue  Bridge  Over  Fort 
Point  Channel  and  its  Approaches.   Plans 
have  been  advanced  for  a  new  fixed-span 
Northern  Avenue  bridge  approximately 
200  feet  southwest  of  the  antiquated 
existing  bridge.   An  EIS  has  been 
completed  by  the  MDPW  and  final  engineering 
studies  await  the  outcome  of  final 
determination  of  the  historic  worth  of  the 
existing  bridge  and  the  issues  of 
navigation  of  the  Fort  Point  Channel. 
Northern  Avenue  and  its  bridge  is  the 

most  important  and  heavily  used  traffic 
link  betweek  South  Boston  and  Boston 
Proper.   The  bridge  is  vital  for  smooth 
flow  of  present  and  future  traffic  and 
for  improvement  of  commercial  and 
residential  life  in  the  adjacent  and 
deteriorating  areas. 

8.  Lafayette  Place.   As  part  of  continuing 
efforts  to  strengthen  the  retail  shopping 
core  of  downtown,  Lafayette  Place  has  been 
designed  to  house  new  shops,  expansion 
room  for  a  major  department  store,  and 
parking  for  shoppers.   The  major 
transportation  impacts  result  from  the 
proposed  alterations  to  the  downtown 
street  pattern.   Essex  Street  is 
proposed  to  become  a  major  connector 

into  the  new  development,  tying  to  the 
Artery  corridor  at  Atlantic  Avenue.   The 
new  street  would  be  two-way,  and  would 
link  to  the  South  Station  area  near 
Dewey  Square.   New  parking  would  be 
approached  from  the  street,  and  major 
connections  to  the  Artery  corridor  would 
be  essential  for  ready  service  to  the 
proposed  parking  facilities. 

138 


9.      South   Station   Transportation   Center. 
The   most   important   new   traffic 
generator   in    the   South  Area   is    the 
proposed   82 -acre    South   Station 
Transportation   Center,    presently   owned 
by   the   BRA  and   scheduled   to   be   rebuilt 
by    19  80    as    an    "intermodal   transportation 
center"    serving  Amtrak    inter-city 
trains    and   MBTA  commuter  and   rapid   transit 
trains.      Public   improvements,    totaling 
over   $100   million,    will   include   reno- 
vation  of  the  existing   "head  house," 
and  construction   of  a  passenger 
facilities    center  and   a   rail,    bus   and 
auto    transportation    terminal.      An   EIS 
has   been    completed   and   reconstruction   of 
the   old   "head  house"    has   begun.       The 
upper   levels   of  the  new   Transportation 
Center  will   provide    up    to   2,500 
parking  spaces   and  may  connect   directly 
to   the    Southeast  Expressway   and 
adjacent   streets. 

10.      Cross town   Street,    South   End.      The   BRA 
is    currently   designing   the   portion  of 
the   Southwest   Corridor  Arterial    Street 
that   runs    from  Massachusetts   Avenue    to 
Tremont   and  Columbus   Avenues.      At 
Massachusetts   Avenue,    the   street   ties 
directly   to   ramps   of   the   Central 
Artery.      Construction  of  the    arterial 
street  has   been   declared   a   non-major 
action.      Actual    construction   of   the 
arterial   will   be   undertaken   by   the 
Massachusetts    Department  of   Public 
Works. 


139 


■ 


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I.   INTRODUCTION 


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The  following  material  provides  technical  backup 
on  the  approach  and  methods  used  in  analyzing 
benefits,  impacts,  and  costs  for  alternative 
South  Area  Central  Artery  improvements  considered 
in  the  Central  Artery/I-93  Corridor:  South  Area 
Planning  Study.   As  in  the  Study,  four _ areas _o± 
impact  analysis  are  considered:  operational  im- 
provements and  benefits,  design  standards  and 
safety,  environmental  and  community  impacts,  and 
construction  costs  and  impacts.   Each  of  these 
is  considered  with  regard  to  the  various  con- 
struction options  developed  in  the  Study.   In 
some  cases,  methods  of  analysis  have  been  taken 
up  fully  in  the  Study,  and  require  little  further 
treatment  here.   In  others,  it  was  appropriate 
that  analysis  details  be  reserved  for  this  docu- 
ment.  The  methods  used  are  consistent  with  the 
"state  of  the  art"  in  highway  planning  practice. 
Sometimes  they  are  qualitative,  and  sometimes 
quantitative,  depending  on  suitability  as  re- 
lated to  the  particular  impact  category  being 
assessed.   Also,  in  analyzing  benefits,  a 
conservative  approach  has  been  taken  to  assure 
that  results  would  not  overstate  the  worth  of 
proposed  investments.   Finally,  it  should  be 
noted  that  the  analyses  are  at  this  point 
approximate.   While  the  methods  used  have  prob- 
ably yielded  results  of  the  proper  general 
ordering  and  magnitude,  certain  results  can  be 
expected  to  change  somewhat  as  improved  data 
become  available  and  future  detailed  studies 
are  xmdertaken. 


For  convenience,  each  of  the  construction 
options  considered  is  described  briefly  below: 

Alternative  1. 

The  No  Build  Alternative  has  been  developed  to 
explore  the  possibility  of  retaining  the  existing 
facility  with  some  modifications  to  prolong  its 
useful  life.   South  of  the  Dewey  Square  Tunnel, 
the  Artery  decks  need  replacement  in  the  near 
future  if  no  other  improvements  are  made.   In 
the  Dewey  Square  Tunnel  area,  modifications 
could  range  from  minor  changes  to  the  tunnel, 
to  widening  by  adding  new  lanes. 


Alternative  2. 

This  is  similar  to  Alternative  1,  except  for 
the  addition  of  construction  of  a  special 
purpose  Third  Harbor  Tunnel.   The  connection 


between  the  South  Area  and  the  tunnel  would  be 
made  in  the  vicinity  of  the  Turnpike  and  Artery 
interchange.   The  two-way  tunnel  would  be 
located  in  the  Fort  Point  Channel. 

Alternative  3. 


This  is  similar  to  Alternative  2,  except  that 
the  tunnel  would  be  a  general  purpose  Third 
Harbor  Crossing. 

Alternative  4. 


In  this  alternative,  the  South  Area  of  the  Artery 
would  be  reconstructed  to  provide  a  new  north- 
bound tunnel  of  three  lanes  and  a  breakdov;n 
lane,  to  be  located  under  either  Atlantic  Avenue 
or  the  Fort  Point  Channel.   It  would  be  connected 
to  the  present  Central  section  of  the  Artery  in 
the  vicinity  of  Northern  Avenue.   The  Dewey 
Square  Txinnel  would  be  retained  for  southbound 
movements,  but  could  be  modified  for  better 
geometries  and  lane  configuration.   New  or 
improved  connections  would  be  made  to  local 
streets  and  to  the  proposed  South  Station 
Transportation  Terminal.   Provisions  would  be 
made  for  connections  to  a  third  harbor  tunnel 
if  that  facility  were  to  be  constructed. 

Alternative  5. 


This  is  similar  to  Alternative  4  with  the 
addition  of  a  Special  Purpose  Third  Harbor 
Tunnel. 

Alternative  5. 


Similar  to  Alternative  5  except  that  the  Third 
Harbor  Tunnel  would  be  for  general  purposes. 

Alternative  7. 

In  this  alternative,  the  South  Area  would  be 
reconstructed  as  in  Alternative  4  with  a 
connection  to  a  reconstructed  depressed  Central 
Area  section  of  the  Artery. 

Alternative  8. 


Similar  to  Alternative  7  with  the  addition  of 
a  special  purpose  Third  Harbor  Tunnel. 

Alternative  9. 


Similar  to  Alternative  8  except  that  the  Third 
Harbor  Tunnel  would  be  for  general  purposes. 


II.   OPERATIONAL  IMPROVEMENTS  AND  BENEFITS 

The  assessment  of  operational  impacts  usually 
involves  an  iterative  procedure  which  relates 
traffic  volumes,  design  characteristics,  and 
resulting  travel  characteristics  and  benefits. 
Basic  travel  estimation  for  the  South  Area 
Study  was  carried  out  through  a  manual  traffic 
assignment  procedure  which  utilized  1975  traffic 
volumes,  alternative  system  characteristics,  and 
various  assumptions  regarding  sources  and  flows 
of  future  traffic.   Explicit  analyses  of  queues, 
delays,  and  vehicle  speeds  were  then  undertaken 
based  on  traffic  estimates  and  design  character- 
istics of  the  different  construction  options. 
Travel  time  and  operating  cost  savings  were  then 
calculated  based  on  projected  delays  and  vehicle 
speeds.   Each  of  these  analyses  is  considered 
below. 

A.   Traffic  Estimation 

The  first  step  in  estimating  traffic  for  the 
South  Area  was  to  build  a  base  case  network  for 
the  No  Build  Alternative.   This  network  included 
the  present   express  highway  facilities  in  the 
South  and  Central  areas,  and  the  surrounding 
highways  and  local  streets  that  could  experience 
traffic  impacts  from  South  and  Central  Area 
Artery  improvements.   Once  this  was  completed, 
1975  traffic  volumes  were  assigned  to  the  major 
links  of  the  network.   Since  this  process  was 
completed  before  the  data  became  available  from 
the  Central  Artery  Origin/Destination  survey 
of "March,  1977,  the  best  pre-existing  available 
data  were  used.   Both  MDPW  Automatic  Traffic 
Recorder  counts  for  the  Central  Artery  and  its 
on  and  off  ramps,  and  manual  traffic  counts  from 
the  Citv  of  Boston  Department  of  Traffic  and 
Parking^ were  used  to  determine  1975  7-9  AM  and 
4-6  PM  peak  period  volumes  for  the  No  Build 
alternative.   Manual  adjustments  were  made  to 
balance  traffic  flows  for  internal  consistency^ _ 
and  checks  were  made  for  reasonableness.   Traffic 
volume  data  ranged  from  1972  to  1977  derived 
from  the  various  sources.   Traffic  counts  made 
by  the  Massachusetts  Turnpike  Authority  and 
the  Boston  Redevelopment  Authority  for  special 
projects  were  used  to  work  out  the  final  set 
of  1975  assigned  total  peak  period  volumes. 
Truck  volumes  were  determined  from  the  South- 
east Expressway  Downtown  Express  Lane  evaluation 
program. 

In  assigning  traffic  to  new  or  improved  facilities 
for  the  eight  "Build"  alternatives,  the  following 
assumptions  were  made: 


•  Increased  traffic  volumes  would  occur 
as  a  result  of  route  switching  and  new 
trips. 

•  Most  of  the  "new"  trips  would  be  through 
trips  (approximately  75%) . 

•  An  implied  travel  time  elasticity  of  -1.2 
was  used  to  estimate  increased  travel 
based  on  travel  time  reductions.   Assuming 
South  Area  construction  but  no  Central 
Area  project,  this  resulted  in  an  extra 
300  trips  in  each  direction  during  each 

of  the  peak  periods..  If  the  Central  Area 
were  built  in  addition  to  the  South  Area, 
this  resulted  in  an  extra  500  trips 
in  each  direction  during  each  peak  period. 

•  The  reduction  in  total  numbers  of  ramps 
in  the  various  alternatives  was  not 
assumed  to  reduce  the  n\imber  of  trips. 
These  on  and  off  moves  were  shifted  to 
different  ramps  on  the  Artery.   It  was 
assumed  that  improved  service  levels  on 
the  Artery  would  retain  these  trips. 

•  Approximately  100  trips  each  peak  period 
were  assigned  to  switch  from  Storrow 
Drive  to  the  Massachusetts  Turnpike  due 
to  a  new  third  harbor  tunnel  for  the 
general  purpose  option  only. 

•  Route  diversion  to  the  improved  Artery 
would  occur  only  from  directly  parallel 
routes  such  as  the  existing  surface  streets 
Diversion  to  the  improved  Artery  would 

be  approximately  25%  to  33%  of  existing 
off-Artery  trips  on  these  routes. 

•  The  third  harbor  tunnel  was  assumed  to 
carry  traffic  only  between  Logan  Airport 
and  the  southern  and  western  corridors. 
As  a  special  purpose  facility,  it  was 
assumed  to  carry  buses,  limousines,  taxis, 
trucks,  carpools  (three  or  more  occupants 
per  vehicle),  and  vanpools. 

•  Truck  traffic  was  assumed  to  be  3.5%  of 
total  traffic  in  the  South  Area. 

The  actual  traffic  assignment  procedure  for 
different  alternatives  was  as  follows:  First, 
all  base  case  traffic  was  assigned  to  each  alter- 
native changing  only  the  ramp  volumes  to  reflect 
the  different  ramp  locations.   Second,  estimates 
were  made  of  traffic  diverted  from  parallel  road- 
ways.  These  estimates  were  based  on  increased 
AJTtery  and  ramp  speeds  associated  with  the 


improved  Artery  levels  of  service  that  each 
alternative  would  allow.   As  part  of  this  step, 
new  or  induced  trips  were  estimated  and  added 
to  the  totals  on  the  Artery.   As  in  Step  2,  the 
new  traffic  was  estimated  based  on  the  increased 
speeds  allowed  by  the  proposed  new  construction. 
Again,  ramp  volumes  were  changed  appropriately. 
The  fourth  step  was  to  check  the  final  results 
by  computing  volume/capacity  ratios,  and  deter- 
mining whether  the  Artery  and  ramp  speeds 
assumed  in  the  second  and  third  steps  could  be 
maintained.   If  not,  volumes  on  the  Artery  were 
adjusted  downward,  and  traffic  was  rediverted 
onto  parallel  streets  until  the  assumed  speeds 
could  be  met. 

The  entire  procedure  was  completed  manually 
for  Alternatives  4,  5,  6,  7  and  9.   Alternative 
1  (No  Build),  was,  of  course,  also  done  as  the 
base  case.   Artery  traffic  estimates  for 
Alternatives  2,  3,  and  8  were  interpolated  from 
numbers  for  the  other  alternatives. 

B.   Queues,  Vehicle  Speeds  and  Delays 

In  order  to  calculate  queue  lengths  for  different 
alternatives,  it  is  necessary  to  compare  capacity 
with  demand.   In  the  South  Area  analysis,  the 
procedure  for  estimating  queues  was  drawn  largely 
from  NCHRP  Report  #133  by  Curry  and  Anderson.^ 
Peak  period  demand  from  the  traffic  assignments 
was  compared  with  the  capacities  of  the  alter- 
natives (at  service  level  "E")  for  the  highway 
sections  upstream  from  the  queue,  within  the 
queue,  and  at  the  bottleneck.   This  yielded  rate 
of  queuing  and  speeds  for  the  sections  of  high- 
way.  Rate  of  queuing  was  simply  the  difference 
between  the  demand  at  the  bottleneck  and  the 
capacity  at  the  bottleneck,  expressed  in  vehicles 
per  hour.   Speeds  in  the  non-queuing  sections 
were  determined  from  Curry  and  Anderson  ^see 
Figure  1)  as  a  function  of  volume/capacity. 
The  curve  for  50  MPH  AHS  (design  speed)  was 
used.   Speeds  in  the  queuing  sections  were  also 
determined  from  Curry  and  Anderson  (see  Figure  2). 

In  the  second  stage  of  the  analysis,  queue  length 
was  calculated  as  a  function  of  difference  in 
vehicles  per  mile  within  the  queue,  and  vehicles 


^    David  Curry  and  Dudley  Anderson,  Procedures 

for  Estimating  Highway  User  Cost,  Air  Pollution, 
and  Noise  Effects,  NCHRP  Report  #133,  1972. 


Figure  1:  Running  Speed,  Freeways  -  Passenger  Cars 


65 


60 


X 

2 

55 

O 

UJ 

UJ 

50 

£L 

(Ti 

O 

Z 

4b 

z 

z 

33 

a: 

40 

Ui 

^ 

OL 

35 

30 


25 


O  0.2  0.4 

Volume/Capacity  Ratio 

Source:  NCHRP  *  133,  Figure  A-1 


Figure  2:  Average  Speed  Versus  Volume/Capacity 
Ratio  for  Level  of  Service  F 


0.2 


0.4        0.6 
V/C  RATIO 


o   30 

e 

y 

£ 

y 

/ 

1    '° 
o 

S    15 

Q. 

to 

S  10 

< 

cc 

^     5 
< 

0 

X 

y 

^ 

^ 

_^ 

^ 

^^ 

^ 

^ 

0.8 


1.0 


Source:  NCKRP  #133,  Figure  9 


per  mile  upstream  from  the  queue,  as  related 
to  the  number  of  peak  period  vehicles  that 
could  not  pass  through  the  bottleneck.   Density 
of  vehicles  per  mile  in  the  highway  sections 
was  calculated  by  dividing  the  vehicles  per  hour 
by  the  vehicle  speeds  calculated  earlier.   The 
difference  in  vehicles  per  mile  between  the 
highway  upstream  from  the  queue,  and  the  highway 
within  the  queue  itself,  represented  the  number 
of  vehicles  per  mile  that  the  queue  section 
could  accommodate  by  changing  from  non-queue  to 
queue. 

To  determine  maximum  peak  period  length  of 
queue,  the  following  calculation  was  made: 

Maximum  Lane  Miles  of  Queue  = 

Hours  in  Peak  x  Vehicles  per  Hour 

to  Enter  Queue  


Number  of  Vehicles  per  Lane  Mile  that 
Queue  can  Accept 

The  average   length  of  peak  period  lane  miles  of 
queue  was  the  above-calculated  figure  divided 
by  2.   To  finally  determine  the  average  length 
of  highway  having  a  queue  dur^-ng  the  peak 
period,  the  average   lane  miles  of  queue  were 
divided  by  the  number  of  lanes  in  the  section 
of  highway  affected. 

South  Area  vehicle  speeds  and  delays  came 
directly  from,  the  queuing  analysis.   Area  vehicle 
speeds  for  each  alternative  were  determined  by 
averaging  the  speeds  in  the  different  highway 
sections  upstream  of,  within,  and  beyond  the 
queue,  with  the  averages  weighted  by  the  lengths 
of  the  sections  involved.   Delays  were  calculated 
from  vehicle  speeds.   To  do  this,  total  travel 
times  were  calculated  for  each  alternative  by 
multiplying  average  speeds  for  the  highway  sections 
by  the  average  demand,  and  adding  together  the 
results  for  the  sections.   These  results  were 
then  normalized  to  base  case  volumes  in  order 
to  allow  comparability.   Delay  reductions  were 
then  the  differences  between  total  normalized 
travel  times  for  the  alternatives,  and  the 
total  travel  time  that  would  prevail  for  the 
base  or  No  Build  case. 

C.   Travel  Time  Value  and  Savings 

Travel  time  is  one  of  the  most  important 
technical  inputs  for  determining  the  extent, 
nature,  and  structure  of  transportation 
facilities.   It  is  often  the  basis  for  selecting 


a  particular  routing  of  traffic,  and  is  used 
in  many  trip  allocation  studies  as  a  part  of 
forecasting  facility  use. 

For  many  years,  it  has  been  the  practice  in 
highway  economy  studies  to  price  travel  time  in 
dollars.   In  most  instances,  the  value  of  time 
has  been  determined  either  through  inferring 
traveler  values  by  analyzing  their  choices  of 
modes  or  routes,  or  through  studying  wage 
rates.   In  this  analysis  both  approaches  have 
been  used.   For  auto  drivers,  auto  passengers, 
and  bus  passengers,  time  values  were  derived  by 
using  results  from  route  and  mode  choice  studies 
that  were  conducted  in  situations  analogous  to 
that  of  the  Central  Artery.   A  value  of  time  for 
these  classes  of  travelers  was  established  at 
$4.30  per  hour.   For  buses,  commercial  vehicles, 
and  their  drivers,  information  on  non-distance 
related  costs  (e.g.,  insurance  and  depreciation) 
and  on  driver's  wage  rates  was  used.   Time 
savings  for  both  buses  and  commercial  vehicles 
were  valued  at  $10.00  per  hour. 

The  actual  determination  of  travel  time  value 
for  auto  occupants  and  bus  passengers  was  based 
on  methods  and  results  from  two  studies,  one  by 
Thomas,^  and  the  other  by  Lisco.^   These  studies 
were  conducted  under  highly  selected  conditions 
that  were  related  in  several  ways  to  those  in 
the  South  Area.   First,  the  values  derived 
applied  solely  to  urban  peak-period  commuting. 
Second,  the  values  related  only  to  persons  on 
their  home-to-wor.k  or  work-to-home  journeys. 
Also,  they  applied  to  middle  to  upper-middle 
class  suburbanites.   The  values  of  the  two 
studies  were  developed  in  1966  and  1967, 
respectively. 

Thomas  offers  the  only  important  route  choice 
contribution  in  the  area  of  revealed  commuter 
behavior.   His  research,  based  on  driver 


-^  T.  C.Thomas,  The  Value  of  Time  for  Passenger 
Cars,  An  Experimental  Study  of  Commuters' 
Values,  Vol.  II  of  a  report  prepared  by  Stanford 
Research  Institute  for  the  U.S.  Bureau  of  Public 
Roads,  May,  1967. 

3  Thomas  Lisco,  The  Value  of  Commuters'  Travel 

Time.-  A  Study  in  Urban  Transportation,  doctoral 
dissertation,  University  of  Chicago,  June,  1967. 


behavior  in  eight  cities,  recommended  a 
commuting  time  value  of  $2.80  per  hour.   Lisco, 
whose  analysis  was  conducted  in  the  Chicago 
area,  used  a  mathematical  model  similar  to 
that  used  in  the  Thomas  study.   His  data, 
however,  came  from  a  sample  of  commuters  who 
faced  a  trade-off  situation  between  automobiles 
and  public  transit.   The  Lisco  study  arrived  at 
a  time  value  of  $2.50  per  hour. 

Although  the  results  of  either  of  these  two 
studies  could  have  been  adjusted,  updated  and 
applied  to  the  Central  Artery  situation  with 
little  difference  in  the  overall  outcome,  the 
Lisco  results  were  actually  used.   This  was 
partly  because  the  Lisco  study  involved  both  auto 
and  transit  users,  and  partly  because  it  allowed 
simple  adjustments  for  use  in  the  Boston  area. 
In  order  to  apply  the  Chicago  results  to  Boston, 
two  corrections  were  necessary.   These  were  to 
reflect  the  fact  that  time  value  correlates 
closely  with  income,  and  to  account  for  inflationary 
changes.   The  first  correction  was  an  adjustment 
to  make  Chicago  time  values  in  1967   comparable 
to  those  in  Boston  at  that  time.   To  do  this,  the 
Chicago  value  of  $2.50  per  hour  was  lowered  to 
$2.45  for  Boston  to  account  for  the  approximate 
2%  difference  in  median  incomes  between  Illinois 
and  Massachusetts  that  prevailed  in  1967.   The 
second  correction  was  to  adjust  for  inflationary 
and  real  income  changes  in  Massachusetts  between 
1967  and  1975.   This  involved  a  simple  projection 
of  the  1967  Boston  value  to  1975  using  a  ratio  of 
1975  to  1967  Massachusetts  median  incomes. ^   This 
yielded  the  final  time  value  of  $4.30  per  hour 
for  auto  occupants  and  bus  passengers. 

To  determine  the  value  of  travel  time  savings 
for  trucks  and  buses,  values  developed  by 
Adkins,  Ward,  and  McFarland  were  utilized.^ 
Based  on  data  published  by  the  U.S.  Department 
of  Labor,  Bureau  of  Labor  Statistics,  the 


4  "Money  Income  and  Poverty  Status  of  Families 
and  Persons  in  the  United  States:  1975  Re- 
visions (Advance  Report),"  U.S.  Department  of 
Commerce,  Bureau  of  the  Census  -  Series  P-06 
#103,  issued  Sept.,  1976. 

5  W.G.  Adkins,  W.W.  Allen,  and  W.F.  McFarland, 
Values  of  Time  Savings  of  Commercial  Vehicles, 
NCHRP  Report  #33,  1967. 


authors  compared  vehicle  interest,  depreciation, 
and  taxes  on  an  hourly  basis  to  establish  the 
values  of  vehicle  time  for  commercial  vehicles 
throughout  various  regions  of  the  U.S.   Then 
they  added  to  these  values,  driver's  wages, 
welfare,  workmen's  compensation,  and  FICA  taxes. 
The  total  hourly  costs  for  trucks  in  the  New 
England  area  in  1965  came  to  $4.8  9  per  hour, 
and  those  for  buses  to  $4.97.   Using  changes  in 
price  indices    and  recent  U.S.  Department  of 
Labor  statistics^,  these  figures  were  updated  in 
the  South  Area  Study,  respectively,  to  $9,90  per 
hour  for  trucks  and  $10.00  per  hour  for  buses. 
For  purposes  of  measuring  South  Area  benefits, 
both  figures  were  assumed  to  be  $10.00  per  hour. 

To  apply  the  calculated  time  values ,  it  was 
necessary  to  determine  the  appropriate  volumes 
of  passengers  and  vehicles.   To  apply  the  time 
value  savings  of  auto  occupants,  information 
was  necessary  on  auto  occupancy.   For  this 
purpose,  counts  were  taken  by  the  MDPW  during 
the  morning  peak  period  both  in  the  North  Area 
of  the  Central  Artery,  and  at  Southampton 
Street  on  the  Southeast  Expressway.   The  average 
auto  occupancy  for  the  North  Area  was  estimated 
at  1.40  passengers  per  vehicle,  and  at  South- 
ampton Street,  the  estimate  was  1.30.   Thus,  for 
purposes  of  calculating  travel  time  benefits  for 
the  South  Area,  an  average  peak  period  auto 
occupancy  of  1.35 'was  assumed. 

Based  on  bus  counts  taken  as  part  of  the  South- 
east Expressway  Downtown  Express  Lane  evaluation 
program,  total  numbers  of  buses  were  estimated. 
The  average  peak  period  occupancy  rate  was  assumed 
to  be  40  passengers  per  bus.   The  analysis  did 
not  assume  any  sort  of  preferential  lane  for 
buses  in  the  South  or  Central  Areas. 

Finally,  it  was  necessary  to  determine  the  total 
number  of  trucks.   This  figure  was  taken  from 
the  same  sources  used  in  the  traffic  estimation 
procedure.   Trucks  were  estimated  at  3.5%  of 
total  traffic  volumes. 

In  estimating  the  values  of  total  time  savings 
associated  with  the  various  alternatives,  a 
conservative  approach  was  used.   Benefits  were 
calculated  only  for  the  AM  and  PM  two  hour  peak 
periods  for  the  260  workdays  per  year,  and  only 


b  Bulletin  #1917,  U.S.  Department  of  Labor, 
Bureau  of  Labor  Statistics. 


for  users  of  the  South  Area  section  of  the 
Central  Artery.   As  in  the  case  of  the  delay 
analyses,  benefits  from  implementation  of  pro- 
posed improvements  elsewhere  in  the  corridor 
were  included  only  insofar  as  they  would  be 
experienced  in  the  South  Area.   Benefits  to 
travel  on  local  streets  were  not  included. 

D.   Vehicle  Operating  Cost  Savings 

Exclusive  of  travel  time  and  accident  costs, 
operating  costs  of  a  vehicle  when  on  the  highway 
consist  of  fuel,  oil,  tires,  depreciation,  and 
maintenance.   Other  costs,  such  as  license  fees, 
insurance,  parking  fees,  tolls,  garage  rental, 
and  interest  charges  are  not  closely  related  to 
design  of  a  highway  or  to  traffic  conditions,  and 
thus  can  be  omitted  from  economic  analysis  of 
highway  options. 

A  review  of  the  literature  revealed  three  major 
sources  of  information  on  vehicle  operating  costs 
in  the  U.S.:  Winfrey,"^  Claffey,^  and  Curry  and 
Anderson. 5   since  Curry  and  Anderson  utilized 
the  work  of  Winfrey  and  Claffey,  and  also  allowed 
straight- forward  application,  the  Curry  and 
Anderson  work  was  used  to  develop  South  Area 
operating  costs. 

The  actual  procedure  for  calculating  operating 
costs  had  two  parts  and  was  done  separately  for 
automobiles  and  trucks.   In  the  first  part  of 
the  analysis,  base  case  operating  costs  were 
developed-   These  assumed  the  present  level  of 
service  "F"  prevailing  on  the  South  Section  of 
the  Central  Artery  during  peak  periods,  and 
included  an  inflation  factor  to  cover  cost 
increases  from  1970,  the  year  of  the  Curr^'  and 
Anderson  cost  indices,  to  1975.   In  the  second 
part  of  the  analysis,  operating  costs  for  the 
various  alternatives  were  related  to  operating 
speeds,  again  with  the  given  inflation  factor. 
The  following  sections  describe  the  specific 
procedures  used,  respectively,  for  automobiles 
and  trucks. 


7  Robley  Winfrey,  Economic  Analysis  for  Highways, 
(International  Textbook  Company,  1969) . 

8  Paul  Claffey,  Running  Costs  of  Motor  Vehicles 
as  Affected  by  Road  Design  and  Traffic,  NCHRP 
Report  #111,  1971. 

9  Curry  and  Anderson,  loc.  cit. 

11 


1.   Automobile  Operating  Costs 

Base  case  operating  costs  for  automobiles  came 
directly  from  Curry  and  Anderson.   Figure  3_ 
shows  automobile  operating  costs  as  a  function 
of  Volume/Capacity  CV/C)  ratio  for  level  of 
service  "F".   As  can  be  seen,  costs  per  1,000 
vehicle-  miles  drop  rapidly  until  a  V/C  ratio  of 
about  .4,  and  then  remain  relatively  stable  after 
that.   Assuming  a  V/C  ratio  of  .8,  (which  probably 
yields  a  conservative  estimate  of  automobile 
operating  cost  on  the  Artery) ,  this  would  imply 
a  base  automobile  operating  cost  in  1970  of 
$62.00  per  1,000  vehicle  miles. 

igure  3:  Automobile  Operating  Cost  Versus  Volume/Capacity 
Ratio  for  Level  of  Service  F 


o 
u 


C 


3 

o 


o 

■o 


)- 

o 
u 


125 


100 


75 


50 


1 

1 

— \ — 

\ 

A] 

\^ 

.^^ 

-— 

a2 


0.4  0.6 

V/C   RATIO 


0.8 


1.0 


Source:  NCHRP  #  133,  Figure  13 


To  provide  an  appropriate  inflation  factor  from 
the   1970  Curry  and  Anderson  costs,  an  analysis 
was  undertaken  of  the  individual  cost  components 
of  automobile  operation.   Analysis  by  the  MDPW 
revealed  increases  in  the  costs  of  individual 
items  ranging  from  25%  to  911.  These  are  shown 
in  Figure  4.   Based  on  the  various  component 
costs  and  cost  increases,  a  conser'/ative  estimate 
was  made  that  overall  automobile  operating  costs 
increased  35%  between  1970  and  1975.   Applying 


12 


Figure  4 :  Road  User  Costs  for  Passenger  Vehicles 
1970  and  1975 


Cost  Item 

Unit  Price 
or  Factor  for 
Passenqer  Cars 

Percent 
Increase 
Over  1970 

1970^ 

19752 

Fuel  ($/callon 
excluding  tax) 

0.24 

0.46 

91 

Engine  Oil 
($/quart) 

0.72 

1.00 

39 

Tires 
($/tire) 

30.00 

40.00 

33 

Depreciation 
(Vehicle  base 

3400.00 

4200.00 

23 

price) 

Maintenance 

25 

Source:  1  NCHRP  #133 

2  MDPW  staff  analysis 


this  to  the  $62.00  per  1,000  vehicle  miles  cost 
for  1970,  yielded  a  base  case  cost  of  $83.70  for 
1975. 

Operating  cost  estimates  for  the  various  South  Area 
Study  alternatives  came  from  the  queuing  analysis 
and  from  Curry  and  Anderson.   As  part  of  the 
queuing  analysis,  vehicle  speeds  and  volumes  were 
developed  for  each  link  of  each  alternative  for 
peak  period  travel.   The  vehicle  speeds  were 
applied  to  Figure  5  (from  Curry  and  Anderson)  which 
relates  vehicle  speed  to  Volume/Capacity  ratio, 
and  Volume/Capacity  ratio  to  operating  cost.   The 
50  MPH  Average  Highway  Speed  (design  speed)  curves 
were  used.   Using  the  individual  per  mile  operating 
costs  derived  from  vehicle  speeds,  total  automobile 
operating  costs  for  each  alternative  were  developed 
by  multiplying  the  link  per  vehicle  mile  costs  by 
the  link  vehicle  miles,  and  then  adding  the  totals 
together.   After  that,  the  35%  inflation  factor 
was  added,  and  a  final  3.5%  downward  adjustment 
was  made  to  reflect  the  fact  that  only  96.5%  of 

'peak^peri'od  Central  Artery  traffic  volume  is 

"automobiles.  (3.5%  is  trucks) 


13 


Figure  5  :    Running   Speeds    and   Costs    for   Passenger   Cars    on   Freeways 
60 


r 

2 

O 

UJ 

UJ 

a. 
(/) 

o 


2 
13 

UJ 
O 

< 

cr 

UJ 

> 


r 

UJ 

> 

o 
o 

o 

tn 

cr 

_) 
o 
o 


If) 
o 
u 

o 

2 
2 
3 

cr 


0  0.2 

Source:    NCHRP    #133,    Figure   A-1 


0.4  0.5 

V/C    RATIO 


0.8 


1.0 


14 


2.   Truck  Operating  Costs 

The  procedure  for  developing  truck  operating 
costs  was  analogous  to  that  used  for  automobiles. 
Figure  6  shows  truck  operating  costs  at  level  of 
service  "F".   Assuming  a  V/C  ratio  of  0.8,  this 
gives  a  1970  operating  cost  for  trucks  of  $245.00 
per  1,000  vehicle  miles.   Individual  components 
of  truck  operating  costs  are  shown  in  Figure  7. 
As  seen  in  the  figure,  truck  operating  cost 
components  rose  much  more  than  those  for  auto- 
mobiles during  the  period  1970-1975.   The 
increases  ranged  from  35%  to  525%.   Based  on  the 
numbers  shown  in  the  figure  and  on  the  assumption 
that  fuel  was  a  major  truck  operating  cost,  it 
was  conservatively  estimated  that  overall  truck 
operating  costs  rose  67%  between  1970  and  1975. 
This  yielded  a  1975  base  case  truck  operating 
cost  of  $410.50  per  1,000  vehicle  miles. 

To  calculate  total  truck  operating  costs  for  the 
alternatives,  link  volumes  and  speeds  were  used 
as  before,  and  applied  to  the  50  MPH  AHS  curves 
of  Figure  8,  which  relates  truck  vehicle  speeds 
to  operating  costs.   The  only  difference  here 
between  the  truck  and  automobile  analyses  was 
that  for  trucks  the  67%  inflation  factor  was 
used,  and  that  calculations  were  based  on  the 
3.5%  fraction  of  total  traffic  volume  that 
trucks  represented. 

To  complete  the  operating  cost  analysis,  the 
results  for  trucks  and  for  automobiles  were 
added  together  for  each  of  the  alternatives. 
Cost  savings  were  the  difference  in  operating 
costs  between  the  base  case  (No  Build)  costs 
and  the  calculated  costs  of  the  various 
alternatives . 

HL.  DESIGN  STANDARDS  AND  SAFETY 

A.   Accidents 

A  considerable  body  of  research  has  demonstrated 
the  close  relationship  between  highway  design 
standards  and  safety.   In  spite  of  extensive 
analysis,  however,  there  still  remains  insufficient 
information  to  accurately  predict  future  accident 
experience  for  many  proposed  facilities.   In 
particular,  while  there  are  good  sources  of  in- 
formation to  use  in  estimating  accident  reduc- 
tions associated  with  minor  spot  improvements, 
research  still  falls  short  of  making  possible 
highly  accurate  predictions  of  accident  reductions 
from  major  improvements  to  such  complicated 


Figure  6 :  Truck  Operating  Cost  Versus  Volume/Capacity 
Ratio  for  Level  of  Service  F 


300 


I 


c 


3 
O 


275 


250 


o 
■o 


(A 

•- 
M 
O 

u 


225 


200 


\ 
\ 

\ 

\ 

-^ 

\ 

k 

\ 

Source:  NCHRP  #133,  Figure  13 


.gure'  7 :  Road  User  Costs  for  Commercial  Vehicles 
1970  and  1975 


Cost  Item 


Unit  Price 
or  Factor  for 
Trucks 


Percent 
Increase 
Over  1970 


1970- 


1975- 


Fuel  ($/gallon 
excluding  tax) 


0.16 


0.31 


93 


Engine  Oil 
($/quart) 


C.20 


1.25 


525 


Depreciation 
(Vehicle  base 
price) 


22,600.00     unknown 


Maintenance 


35 


Source: ' ^  NCHRP  #133 

2  MDPW  staff  analysis 


16 


Figure  8:  Running  Speeds  and  Costs  for  Trucks 
on  Freeways 

60 


X 
Q. 

O 
LJ 
UJ 
Q. 
CO 

O 

z 


3 
cr 

lij 
o 

< 
cr 

UJ 

> 
< 


X 
UJ 

> 

o 
o 
o 

in 

tr 


o 
o 


(n 
o 
o 

o 

z 


cr 


O  0.2  0.4  0.5 

V/C    RATIO 

Source:  NCHRP  #  133,  Figure  A-3 


1.0 


17 


areas  as  the  South  Area  of  the  Central  Artery. 
As  a  result,  predictive  techniques  to  forecast 
probable  accident  reduction  rates  associated  with 
South  Area  alternatives  must  be  somewhat  gener- 
alized. 

In  developing  a  method  for  projecting  the  Artery's 
future  accident  experience,  two  assumptions  were 
made.   The  first  was  that  it  would  be  reasonable 
to  assume  that  the  excessive  nvimbers  of  accidents 
on  the  Artery  are  caused  at  least  in  part  by  the 
combined  total  of  its  design  problems.   Second, 
it  was  assumed  that  the  high  volume  of  traffic 
relative  to  the  capacity  of  the  Artery  facility, 
and  particularly  the  amount  of  queuing,  also 
contributes  to  the  Artery's  high  accident  rate. 
Reflecting  these  assumptions,  a  method  for  pro- 
jecting future  accidents  was  developed  which 
depended  both  on  the  degree  to  which  the  improved 
Artery  would  conform  with  Urban  Interstate  design 
standards,  and  the  degree  to  which  future  peak 
period  queues  would  be  eliminated. 

Specifically,  the  method  initially  assumed  that 
the  accident  rate  on  portions  of  the  improved 
Artery  that  met  Urban  Interstate  design  stan- 
dards would  drop  from  that  of  the  present 
facility  to  the  average  rate  for  Urban  Inter- 
state facilities  in  Massachusetts  for  1975 
(1.34  accidents  per  million  vehicle  miles  of 
travel).   Portions  not  brought  into  conformance 
with  Urban  Interstate  standards  would  have  an 
accident  experience  the  same  as  that  prevailing 
in  the  South  Area  of  the  Artery  in  1975.   The 
initial  future  accident  rate  calculation  was 
based  on  the  number  of  miles  of  future  South 
Area  facility  that  would  conform  to  Urban  Inter- 
state standards  as  a  fraction  of  total  miles  of 
the  South  Area  facility.   Accidents  were  pro- 
jected based  on  vehicle  miles  and  on  the  normalized 
link  volumes  derived  in  the  traffic  assignments 
for  the  alternatives. 

In  the  second  state  of  the  accident  projection 
technique,  it  was  assumed  that  the  initially 
projected  future  reductions  in  accident  rates 
would  be  achieved  only  in  proportion  to  the 
degree  to  which  queues  were  reduced.   If  a 
particular  alternative  had  no  queue  reduction 
(e.g.,  the  No  Build -^Alternative  in  the  north- 
bound direction)  ,  no  accident  reduction  would 
take  place.   If  the  alternative  completely 
removed  the  queue,  it  would  yeild  all  the 
accident  reduction  benefits  that  its  conformance 
with  Urban  Interstate  Design  would  allow.   If 


it  were  associated  with  partial  elimination  of 
the  queue,  the  accident  reduction  would  be  in 
proportion  to  the  length  of  queue  eliminated  as 
a  fraction  of  the  total  "No  Build"  queue. 

As  a  practical  matter,  the  two-stage  analysis 
of  potential  accident  reduction  was  carried  out 
in  its  entirety  only  for  the  northbound  roadway. 
Since  there  is  no  queue  southbound  on  the  South 
Section  of  the  Artery,  southbound  accidents 
were  projected  based  on  the  proportion  of  South 
Area  Artery  accidents  occurring  on  the  south- 
bound lanes  during  1975,  and  on  the  degree  to 
which  Urban  Interstate  design  standards  would 
be  met  in  the  reconstructed  facility.   North- 
bound, the  analysis  depended  on  the  fraction  of 
northbound  accidents  in  1975,  on  the  proportion 
of  improved  facility  that  would  meet  Urban  Inter- 
state standards,  and  on  queue  reduction. 

In  the  accident  analysis,  accidents  by  sub- 
categories were  projected  based  on  their  relative 
frequencies  in  1975.   No  attempt  was  made  to 
project  accidents  on  local  streets  in  the  South 
Area.   It  is  expected  that  improved  signal 
systems  coupled  with  proper  channelization  and 
more  standardized  geometries  will  greatly  improve 
safety  on  local  streets.   Quantification  of  the 
safety  results  of  these  improvements  must  wait 
until  the  design  alternatives  are  planned. 

B.   Accident  Costs 

Associated  with  accidents  are  siibstantial  costs, 
not  only  for  injuries  and  deaths,  but  also 
for  property  damage.   As  with  time  savings,  it 
has  long  been  the  practice  of  calculating 
accident  loses  in  dollar  values.   Considerable 
literature  has  attempted  to  evaluate  the  costs 
of  accidents,  particularly  those  involving 
injuries  and  fatalities.   In  this  literature, 
one  of  the  most  comprehensive  studies  was  con- 
ducted by  the  National  Highway  Traffic  Safety 
Administration  of  the  U.S.  Department  of 
Transportation,  in  1972.1°  This  study  developed 
societal  costs  for  traffic  injuries  and  deaths 
for  the  base  year,  1971.   The  estimated  societal 
costs  included  both  lost  wages  and  additional 
services  required  because  of  accidents.   Lost 


m  Societal  Costs  of  Motor  Vehicle  Accidents, 

Preliminary  RepoTtT  National  Highway  Traffic 
Safety  Administration.  U.S.  Department  of 
Transportation,  1972. 


19 


wages  were  of  the  persons  directly  affected; 
services  were  for  hospital  costs,  funeral  costs, 
and  the  like.   The  NHTSA  study  established  the 
societal  cost  of  a  traffic  fatality  at  $200,000, 
and  that  of  an  average  accident  injury  at  $7,300. 

A  subsequent  study  by  the  NHTSA  and  the  Trans- 
portation Systems  Center  of  the  U.S.D.O.T.  up- 
dated the  1971  costs  to  1974.11   This  was  done 
by  multiplying  the  proportion  of  total  1971  cost 
that  was  due  to  service  costs,  similarly  com- 
pounded over  the  three  years  by  service  cost 
increase  factors.   The  resulting  total  increase 
factor  was  then  applied  to  the  1971  costs. 

The  specific  formulas  used  for  these  calculations 
were  as  follows: 

Ld74   =   Ld71  [Wovid+^W^l)  (1+^W72)  (l+'iW73)  + 

Sd7]_(1+4S-7^)  (1+^S72)  (l+^S-73)] 

and 


Si7i{l+4S73_)  (1+4S-72)  (I+4S73)] 


where 

■^D74     Societal  cost  of  a  death  in  1974. 

■'-'D71     Societal  cost  of  a  death  in  1971. 

^D71    Fraction  of  total  societal  cost  of  a 
death  in  1971  due  to  lost  wages. 

'^^7i    Wage  increase  factor  for  given  year  in 

terms  of  rate  of  wage  increases  experienced 
during  that  year. 

^D71     Fraction  of  total  societal  cost  of  a  death 
in  1971  due  to  service  costs. 

•'^7x     Service  cost  increase  factor  for  given 
year  in  terms  of  rate  of  service  cost 
increases  experienced  during  that  year. 

1^175     Societal  cost  of  an  average  injury  in  1974. 

^171     Societal  cost  of  an  average  injury  in  1971. 


11  Analysis  of  Effects  of  Proposed  Changes  to 

Passenger  Car  Requirements  of  xMYSS208  ,  NHTSA 
and  Transportation  Systems  Center,  U.S.  Dept . 
of  Transportation,  August,  1974. 


20 


^'^IVl     Fraction  of  total  societal  cost  of  an 
injury  in  1971  due  to  lost  wages. 

^171    Fraction  of  total  societal  cost  of  an 

injury  in  1971  due  to  costs  of  services. 


Using  these  formulae,  the  1974  study  calculated 
the  updated  cost  of  a  traffic  fatality  at  $242,000, 
and  the  cost  of  an  injury  at  $8,500. 

To  further  update  the  NHTSA  results  to  1975  for 
use  in  the  South  Area  analysis,  an  analogous 
procedure  to  that  described  above  was  used.   The 
respective  wage  cost  proportions  of  total  costs 
for  the  1974  base  were  .677  for  traffic  fatalities 
and  .178  for  injuries.   Correspondingly,  the 
service  cost  proportions  were  .323  and  .822 
for  fatalities  and  injuries,  respectively.   A 
wage  cost  increase  of  .08  was  used  for  increases 
in  wages  during  1974,  and  a  service  cost  increase 
factor  of  . 05  was  used  for  increases  in  the 
costs  of  services.   From  this  second  updating, 
the  total  cost  of  a  traffic  death  in  1975  was 
estimated  at  $259,000,  and  that  of  a  traffic 
injury  at  $9,000. 

With  societal  costs  of  traffic  injuries  and 
fatalities  established,  it  was  necessary  only 
to  determine  average  property  damage  costs  for 
accidents.   These  were  estimated  at  $550  per 
accident  based  on  a  $500  figure  developed  by  the 
National  Safety  Council  for  1974,  escalated  by 
10%  to  1975. 

To  calculate  accident  cost  savings  for  the  South 
Area  alternatives,  the  accident  fatality,  injury, 
and  property  damage  costs  discussed  above  were 
applied  to  the  accident  rates  calculated  for  the 
alternatives.   It  was  assumed  that  fatalities 
and  injuries  would  occur  in  the  same  proportions 
in  the  alternatives  as  they  did  in  the  South 
Area  of  the  Artery  during  1975. 

IV.   ENVIRONMENTAL  AND  COMMUNITY  IMPACTS 

The  South  Area  Study  text  considers   five  areas 
of  environmental  and  community  quality  that  might 
be  affected  by  potential  South  Area  construction: 
air  quality,  noise,  water  quality,  tax  base  and 
development,  and  comm-unity  quality  and  character. 
Two  of  these,  water  quality,  and  community  quality 
and  character,  are  treated  fully  in  the  text, 
and  require  no  further  consideration  here.   The 
others  are  taken  up  below. 

21 


A.  Air  Quality 

The  air  quality  section  of  the  South  Area  text 
is  intended  to  provide  a  basis  for  Environmental 
Impact  Statement  level  studies  of  air  quality 
impact,  and  to  highlight  important  air  quality 
issues  for  further  consideration.   In  line  with 
the  level  of  detail  contained  in  the  preliminary 
traffic  and  other  studies,  a  somewhat  simplified 
calculation  of  air  quality  indices  was  used. 

The  analysis  presented  in  the  air  quality  section 
was  a  determination  of  gross  pollutant  emissions, 
in  tons  of  pollutants  per  year,  generated  by 
traffic  only  on  the  Artery  under  the  various 
alternatives  considered.   In  order  to  carry  out 
this  analysis,  total  vehicle  miles  of  travel  on 
the  South  Section  of  the  Artery  and  on  all  ramps 
were  taken  from  the  traffic  assignments  for  the 
alternatives.   Estimated  1975  peak  hour  volumes 
on  all  links  for  all  alternatives  were  used  to 
synthesize  total  annual  vehicle  miles  of  travel. 
Peak  hour  speed  assumptions  from  the  traffic 
analysis  were  used  for  all  links,  so  that  reported 
estimates  of  CO  and  HC  pollutant  burden  are 
conservative.   The  NO^  totals  are  probably  under- 
estimated, since  NOx  emission  factors  increase 
as  speed  increases. 

All  VMT  totals  computed  were  based  on  1975  travel. 
To  correspond  with  this,  the  emissions  factors 
used  to  calculate  gross  emissions  were  1975  average 
emission  factors  taken  from  Environmental  Protection 
Agency  documentation. -'•^   These  factors  were  speed- 
corrected  for  assumed  operating  speeds  for  each 
link  of  the  Artery  South  Section  using  correction 
formulae  for  light  duty  gasoline  powered  vehicles 
at  low  altitudes.     The  resulting  emissions 
factors  for  different  speeds  are  shown  in 
Figure  9. 

B.  Noise 

Two  approaches  were  used  to  estimate  likely  major 
noise  impacts  of  proposed  South  Area  changes  to 
the  Central  Artery.   First,  field  observations 
were  conducted  along  the  Artery  route  in  the 
South  Area.   Their  purposes  were  to  identify  noise- 


12  Compilation  of  Air  Pollution  Emission  Factors 
Tap  42),  Supplement  5,  Environmental  Protection 
Agency,  1975,  Table  D.8-1. 

13  Ibid.,  Tables  D.1-23  and  D.1-24. 


22 


sensitive  land  uses  affected  by  the  South  Section 
of  the  Artery,  to  locate  important  noise  generators 
other  than  the  Artery  itself,  and  to  supplement 
the  information  obtained  from  earlier  South 
Terminal  and  Central  Artery  data  collection  efforts. 
The  second  procedure  was  a  trial  use  of  the  noise 
prediction  method  described  in  NCHRP  #117,  High- 
way Noise,  A  Design  Guide  for  Highway  Engineers.-'-'^ 

Field  observations  of  the  South  Area  of  the  Artery 
Corridor  yielded  a  number  of  conclusions.   Primary 
among  these  was  the  fact  that  the  Artery  itself 
is, not  the  predominent  noise  generator  in  the 
South  Area.   As  such,  it  adds  only  marginally  to 
existing  Area  noise  levels.   Thus,  potential 
Artery  changes  could  alter  the  noise  levels  in 
the  South  Area  only  to  a  minor  degree.   The 
detailed  conclusions  from  the  field  observations 
are  discussed  more  fully  in  the  South  Area  Study 
text. 


Figure  9 :  Speed  Corrected  Average  Emissions  Factors 


1975  Base  CO 
1975  Base  HC 
1975  Base  NO, 


=  61.10 
=  8.80 
=   4.80 


(Grams  per  Vehicle  Mile) 


AVG.  SPEED  (M.P.H.) 


CO 


HC 


NO3 


5.0 
10.0 
12.0 
15.0 
16.0 
20.0 
21.7 
25.0 
27.2 
28.0 
30.0 
30.8 
34.1 
35.0 
38.0 
40.0 


253.56 
136.25 
136 

78 

74 

59 

55 

47 

42 


25 
46 
16 
93 
06 
19 
89 


41.49 
38.31 


37. 
33. 
32. 
29. 


15 
03 
06 
23 


24. 

14. 

14. 

10. 

10. 
8, 
8, 
7. 
6. 
6. 
6. 


20 
34 
34 
56 
13 
68 
17 
33 
87 
72 
37 


27.66 


6.25 
5.80 
5.70 
5.40 
5.24 


4, 
4 
12 
12 
13 
13 
13 
13 
13 
14 
14 
14 
14 
15 
15 


52 

94 

,94 

58 

68 

10 

,28 

63 

,88 

.97 

.19 

.29 

.67 

.78 

.14 

.38 


14   Colin  Gordon,  et.al. 

Guide  fox  Highway  Engineers, 


Highway  Noise,  A  Design 
NCHRP  Report 


#117,  1971. 


23 


The  second  procedure,  from  NCHRP  #117,  used  a 
mathematical  model  to  simulate  noise  levels.   The 
model  used  is  most  accurate  in  relatively  un- 
developed areas,  where  a  proposed  highway  will 
represent  the  dominent  noise  source  in  the  area 
it  traverses.   It  is  less  useful  in  an  urban 
situation  for  two  reasons.   First,  it  predicts 
the  sound  level  generated  only  by  the  highways 
and/or  streets  modeled.   These  may  not  represent 
the  dominent  noise  sources  in  their  areas  during 
all  hours,  or  even  large  portions  of  the  day. 
Second,  it  generally  has  limited  success  in 
accounting  for  the  complex  shielding  and  reverber- 
ation effects  which  are  characteristic  of  sound 
propagation  in  urban  settings. 

Nonetheless,  it  seemed  appropriate  at  the  Corridor 
Planning  Study  stage  to  undertake  a  trial 
application  of  the  model.   For  this  application, 
shielding  effects  (other  than  those  created  by 
variations  in  the  Artery  profile)  and  complex 
sound  propagation  paths  were  ignored.   In 
addition,  traffic  on  local  streets  was  omitted. 

The  assumptions  used  in  applying  the  NCHRP  #117 
model  were  as  follows:  1.  Traffic  volumes  were 
modeled  only  for  Alternative  1  (No  Build)  and 
Alternative  9  (Maximum  Build-Central  Area  plus 
Split  Alignment  in  the  South  Area  plus  general 
purpose  Third  Harbor  Crossing) .   Only  Artery 
volumes  were  considered,  and  of  these,  only  those 
prevailing  during  the  peak  period  were  used. 
2.   Traffic  speeds  and  voliomes  were  those  from 
the  traffic  analyses  described  earlier.   Link 
speeds  ranging  from  10  to  40  MPH  were  estimated 
for  all  mainline  links;  ramp  speeds  ranged  from 
5  to  15  MPH.   3.   The  truck  percentage  for  the 
Artery  during  peak  periods  was  assumed  to  be  3.5%. 
4.   An  observer  height  of  six  feet  was  used. 

Figures  10  and  11  depict  the  resultant  generalized 
contours  representing  equivalent  A-rtery-generated 
LIO  noise  levels  for  Alternatives  1  and  9, 
respectively.   The  LlO  =  75  dBA  and  LlO  =  7  0  dBA 
values  shown  were  selected  for  reasons  as  follows: 

o  LlO  -  75  dBA.   This  line  was  presented 
because  it  represents  the  exterior  Design 
Noise  Level  for  commercial  and  industrial 
land  uses  appropriate  to  much  of  the  South 
Area.   The  line  defines  what  may  be 


24 


EQUIVALENT  ARTERY- GENERATED    L,o      NOISE  LEVELS 

EXISTING   CASE  ^^^ure    10 


:% 


"//■- 


w7 


i- 


/     / 


^^       ' 


^m^: 


■^ 


;^ 


"-/i 


te4/ 


'L 


:< 


v^^ 


x 


.>^ 


L,o=    75dBA 


L|o=    70dB> 


EQUIVALENT  ARTERY-GENERATED     L,o     NOISE  LEVELS 

MAXIMUM     BUILD    ALTERNATIVE  Figure   % 


considered  as  a  "primary  impact  zone,"  within 
which  the  Artery  itself,  generates  noise 
levels  which  exceed  the  Federal  Highway 
Design  Noise  Level,  regardless  of  the 
contributions  of  other  nearby  sources. 

o  LIO  =  70  dBA.   This  line  represents  the 
Federal  Highway  Design  Noise  Level  for 
residences,  hotels,  schools,  recreation 
areas;  land  uses  which  have  some  represen- 
tation in  the  South  Area.   As  before,  the 
line  denotes  a  "primary  impact  zone"  within 
which  Artery-generated  noise  levels  exceed 
the  Design  Noise  Level  for  the  appropriate 
land  uses. 

As  can  be  seen  in  the  figures,  the  results  of  the 
noise  modeling  generally  supported  the  conclusions 
from  the  field  analyses.   Only  within  the  right- 
of-way  of  the  Artery  itself,  were  simulated  noise 
levels  substantially  above  background  levels  pre- 
vailing generally  in  the  South  Area.    Thus,  the 
contours  shown  could  not  really  demonstrate  the 
Area  noise  environment  either  for  the  present  or 
with  future  construction.   For  this  reason,  further 
noise  simulation  was  relegated  to  the  design 
stages  of  the  South  Area  project,  where  detailed 
noise  analysis  will  be  undertaken.   Such  analysis 
v;ill  incorporate  design  and  building  environment 
details  as  well  as  other  contributors  to  back- 
ground noise  levels. 

C.   Land  Development  and  Tax  Base 

In  the  South  Area  Study  analysis,  land  develop- 
ment potential  was  determ.ined  both  in  terms  of 
land  area  that  would  be  newly  available  for 
development  after  Central  Artery  construction, 
and  in  terms  of  the  value  of  that  land.   Tax 
base  impact  was  not  calculated  directly,  but 
was  projected  in  general  terms  based  on  the 
possibilities  for  new  development. 

New  land  potentially  available  for  development 
was  primarily  the  area  above  any  newly  depressed 
facility.   The  value  of  the  new  land  was  cal- 
culated by  multiplying  the  number  of  square  feet 
available  by  the  market  value  of  such  land.   This 
market  value  was  determined  by  analyzing  recent 
sales  prices.   For  this  purpose,  two  types  of 
land  uses  were  analyzed:  low  intensity  and  high 
intensity.   For  low  intensity  purposes,  land 
was  found  to  have  a  value  of  $32,31  per  square 
foot;  for  high  intensity,  the  value  was  $66.14. 
It  was  assumed  that  any  new  construction  would 
probably  be  a  mixture  of  low  and  high  intensity 
development.   Thus,  actual  land  values  would  be 
somewhere  between  the  low  intensity  and  high 

27 


intensity  figures.   It  was  also  assumed  that  even 
if  developable  land  were  left  as  open  space, 
that  land  would  nonetheless  retain  its  develop- 
ment value. 

In  the  analysis  of  land  value  and  tax  base,  two 
potential  impacts  were  not  included.   One  was 
the  loss  that  would  be  associated  with  taking  the 
Sheraton  Building  (necessary  in  Alternatives  4-9). 
That  building  had  a  1977  assessed  valuation  of 
$6.45  million.   The  other  impact  neglected  was 
the  general  increase  in  property  values  that  would 
take  place  in  the  Artery  Corridor  once  the  negative 
impacts  of  the  Artery  were  removed. 

V.   CONSTRUCTION  COSTS  AND  IMPACTS 

Construction  costs  for  the  South  Area  alternatives 
were  developed  by  the  MDPW  as  part  of  the  1977 
Interstate  Cost  Estimate.   As  such,  they  were 
based  on  cost  indices  that  prevailed  during  1975. 

In  the  cost  estimation  procedure,  costs  were 

first  estimated  for  typical  sections  of  construction 

involved,  e.g.  tunnel,  viaduct,  ramps;  and  for 

normal  accompanying  structures  and  equipment  such 

as  signing,  lighting,  and  ventilation.   Quantities 

of  materials  were  usually  calculated  on  a  lineal 

foot  or  unit  basis.   Costs  for  individual  items 

of  work  were  generrally  developed  from  bid  costs 

for  construction  within  the  Boston  metropolitan  area, 

In-  applying  the  standard  cost  indices  to  the 
alternatives,  estimates  were  made  of  the  lineal 
feet  or  the  numbers  of  units  of  the  various  types 
of  construction  in  each  alternative.   These 
estimates  were  then  applied  directly  to  the  per 
lineal  foot  and  unit  costs  calculated  earlier. 

In  all  cost  estimation,  demolition  costs  were 
included  as  appropriate.   It  was  assumed  that 
the  materials  in  demolished  structures  would 
have  a  zero  net  value. 

Two  types  of  construction  impacts  were  considered 
in  the  South  Area  analysis :  construction  duration 
and  traffic  disruption.   Construction  duration  was 
estimated  based  on  the  experience  of  the  MDPW  in 
earlier  highway  construction  projects.   Potential 
traffic  disruption  associated  with  the  alternatives 
was  broadly  estimated  based  on  staging  require- 
ments and  the  nature  of  construction. 


28 


BIBLIOGRAPHY  , 

Adkins,  W.G.;  Allen,  W.W.;  McFarland,  W.F.: 
"Values  of  Time  Savings  of  Commercial  Vehicles"  , 
NCHRP  #33,  1967. 

Anderson,  Dudley  G.  and  Curry,  David  A.  :  "Pro- 
cedures for  Estimating  Highway  Uaer  Cost,  Air 
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Claffey,  Paul:  "Running  Costs  of  Motor  Vehicles 

as  Affected  by  Road  Design  and  Traffic,"  NCHRP  #111, 

1971. 

Gordon,  C.G.;  Galloway,  W.J.;  Kuglar,  B.A. ;  and 
Nelson  D.L.:  "Highway  Noise  -  A  Design  Guide  for 
Highway  Engineers,"  NCHRP  #117,  1971. 

Lisco,  T.E.:"The  Value  of  Commuters'  Travel  Time  -  A 
Study  in  Urban  Transportation,"  Doctoral  Dissertation 
University  of  Chicago,  1967. 

Thomas,  T.C.:  "The  Value  of  Time  for  Passenger 
Cars:  An  Experimental  Study  of  Commuters'  Values," 
Volume  II  of  a  report  prepared  by  the  Stanford 
Research  Institute   for  the  U.S.  Bureau  of  Public 
Roads,  1967. 

U.S.  Department  of  Commerce,  Bureau  of  the  Census, 
"Money  Income  and  Poverty  Status  of  Families  and 
Persons  in  the  United  States:  1975  and  1974 
Revisions  (Advance  Report),"  Series  P-60,  #103, 
1976. 

U.S.  Environmental  Protection  Agency,  "Compilation 
of  Air  Pollution  Emission  Factors  (AP  42) , 
Supplement  5," 1975. 

U.S.  Department  of  Labor,  Bureau  of  Labor 
Statistics,  Bulletin  #1917. 

U.S.  Department  of  Transportation,  National  Highway 
Traffic  and  Safety  Administration,  and  Transportation 
Systems  Center:  "Analysis  of  Effects  of  Proposed   ^_ 
Changes  to  Passenger  Car  Requirements  of  MVSS  208, 
1974. 

U.S.  Department  of  Transportation,  National  Highway 
Traffic  Safety  Administration:  "Societal  Costs  of 
Motor  Vehicle  Accidents,  Preliminary  Report,"  1972. 

Winfrey,  Robley:  "Economic  Analysis  for  Highways," 
International  Textbook  Company,  1969. 


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